Posting your config between Code-tags is easier for everyone ...
# oct/10/2021 20:57:46 by RouterOS 7.1rc4
# software id = BSM0-IT8B
#
# model = RBD53iG-5HacD2HnD
# serial number = E7290XXXXXXX
/interface bridge
add admin-mac=08:55:31:XX:XX:XX auto-mac=no comment=defconf name=bridge
/interface wireless
set [ find default-name=wlan1 ] band=2ghz-b/g/n channel-width=20/40mhz-XX \
country=poland disabled=no distance=indoors frequency=auto installation=\
indoor mode=ap-bridge ssid=czosnek wireless-protocol=802.11
set [ find default-name=wlan2 ] band=5ghz-a/n/ac channel-width=\
20/40/80mhz-XXXX disabled=no distance=indoors frequency=auto \
installation=indoor mode=ap-bridge ssid=czosnek_5 wireless-protocol=\
802.11
/interface wireguard
add listen-port=13231 mtu=1420 name=wgmt
/disk
set usb1 disabled=no
set usb1-part1 disabled=no
set usb1-part2 disabled=no
set usb1-part3 disabled=no name=disk1
/interface list
add comment=defconf name=WAN
add comment=defconf name=LAN
/interface wireless security-profiles
set [ find default=yes ] authentication-types=wpa2-psk eap-methods="" mode=\
dynamic-keys supplicant-identity=MikroTik
/ip pool
add name=default-dhcp ranges=192.168.1.2-192.168.1.254
/ip dhcp-server
add address-pool=default-dhcp interface=bridge lease-time=1d name=defconf
/interface bridge port
add bridge=bridge comment=defconf interface=ether2
add bridge=bridge comment=defconf interface=ether3
add bridge=bridge comment=defconf interface=ether4
add bridge=bridge comment=defconf interface=ether5
add bridge=bridge comment=defconf interface=wlan1
add bridge=bridge comment=defconf interface=wlan2
/ip neighbor discovery-settings
set discover-interface-list=all
/interface list member
add comment=defconf interface=bridge list=LAN
add comment=defconf interface=ether1 list=WAN
add comment=Wireguard interface=wgmt list=LAN
/interface wireguard peers
add interface=wgmt public-key="XXX="
/ip address
add address=192.168.1.1/24 comment=defconf interface=bridge network=\
192.168.1.0
add address=10.20.50.1/24 comment=Wireguard interface=wgmt network=10.20.50.0
/ip dhcp-client
add comment=defconf interface=ether1 use-peer-dns=no use-peer-ntp=no
/ip dhcp-server network
add address=192.168.1.0/24 comment=defconf gateway=192.168.1.1
/ip dns
set allow-remote-requests=yes servers=1.1.1.1,1.0.0.1
/ip dns static
add address=192.168.88.1 comment=defconf name=router.lan
/ip firewall filter
add action=accept chain=input comment=Wireguard dst-port=13231 \
in-interface-list=LAN protocol=udp
add action=accept chain=input dst-port=13231 in-interface-list=WAN protocol=\
udp
add action=accept chain=input comment=\
"defconf: accept established,related,untracked" connection-state=\
established,related,untracked
add action=drop chain=input comment="defconf: drop invalid" connection-state=\
invalid
add action=accept chain=input comment="defconf: accept ICMP" protocol=icmp
add action=accept chain=input comment=\
"defconf: accept to local loopback (for CAPsMAN)" dst-address=127.0.0.1
add action=drop chain=input comment="defconf: drop all not coming from LAN" \
in-interface-list=!LAN
add action=accept chain=forward dst-address=192.168.1.1 dst-port=13231 \
in-interface=ether1 protocol=udp
add action=accept chain=forward comment="defconf: accept in ipsec policy" \
ipsec-policy=in,ipsec
add action=accept chain=forward comment="defconf: accept out ipsec policy" \
ipsec-policy=out,ipsec
add action=fasttrack-connection chain=forward comment="defconf: fasttrack" \
connection-state=established,related hw-offload=yes
add action=accept chain=forward comment=\
"defconf: accept established,related, untracked" connection-state=\
established,related,untracked
add action=drop chain=forward comment="defconf: drop invalid" \
connection-state=invalid
add action=drop chain=forward comment=\
"defconf: drop all from WAN not DSTNATed" connection-nat-state=!dstnat \
connection-state=new in-interface-list=WAN
/ip firewall nat
add action=masquerade chain=srcnat comment="defconf: masquerade" \
ipsec-policy=out,none out-interface-list=WAN
add action=dst-nat chain=dstnat dst-address=XX.XXX.XXX.XXX dst-port=13231 \
protocol=udp to-addresses=10.20.50.0 to-ports=13231
/ipv6 firewall address-list
add address=::/128 comment="defconf: unspecified address" list=bad_ipv6
add address=::1/128 comment="defconf: lo" list=bad_ipv6
add address=fec0::/10 comment="defconf: site-local" list=bad_ipv6
add address=::ffff:0.0.0.0/96 comment="defconf: ipv4-mapped" list=bad_ipv6
add address=::/96 comment="defconf: ipv4 compat" list=bad_ipv6
add address=100::/64 comment="defconf: discard only " list=bad_ipv6
add address=2001:db8::/32 comment="defconf: documentation" list=bad_ipv6
add address=2001:10::/28 comment="defconf: ORCHID" list=bad_ipv6
add address=3ffe::/16 comment="defconf: 6bone" list=bad_ipv6
/ipv6 firewall filter
add action=accept chain=input comment=\
"defconf: accept established,related,untracked" connection-state=\
established,related,untracked
add action=drop chain=input comment="defconf: drop invalid" connection-state=\
invalid
add action=accept chain=input comment="defconf: accept ICMPv6" protocol=\
icmpv6
add action=accept chain=input comment="defconf: accept UDP traceroute" port=\
33434-33534 protocol=udp
add action=accept chain=input comment=\
"defconf: accept DHCPv6-Client prefix delegation." dst-port=546 protocol=\
udp src-address=fe80::/10
add action=accept chain=input comment="defconf: accept IKE" dst-port=500,4500 \
protocol=udp
add action=accept chain=input comment="defconf: accept ipsec AH" protocol=\
ipsec-ah
add action=accept chain=input comment="defconf: accept ipsec ESP" protocol=\
ipsec-esp
add action=accept chain=input comment=\
"defconf: accept all that matches ipsec policy" ipsec-policy=in,ipsec
add action=drop chain=input comment=\
"defconf: drop everything else not coming from LAN" in-interface-list=\
!LAN
add action=accept chain=forward comment=\
"defconf: accept established,related,untracked" connection-state=\
established,related,untracked
add action=drop chain=forward comment="defconf: drop invalid" \
connection-state=invalid
add action=drop chain=forward comment=\
"defconf: drop packets with bad src ipv6" src-address-list=bad_ipv6
add action=drop chain=forward comment=\
"defconf: drop packets with bad dst ipv6" dst-address-list=bad_ipv6
add action=drop chain=forward comment="defconf: rfc4890 drop hop-limit=1" \
hop-limit=equal:1 protocol=icmpv6
add action=accept chain=forward comment="defconf: accept ICMPv6" protocol=\
icmpv6
add action=accept chain=forward comment="defconf: accept HIP" protocol=139
add action=accept chain=forward comment="defconf: accept IKE" dst-port=\
500,4500 protocol=udp
add action=accept chain=forward comment="defconf: accept ipsec AH" protocol=\
ipsec-ah
add action=accept chain=forward comment="defconf: accept ipsec ESP" protocol=\
ipsec-esp
add action=accept chain=forward comment=\
"defconf: accept all that matches ipsec policy" ipsec-policy=in,ipsec
add action=drop chain=forward comment=\
"defconf: drop everything else not coming from LAN" in-interface-list=\
!LAN
/system clock
set time-zone-name=Europe/Warsaw
/system ntp client
set enabled=yes
/system ntp client servers
add address=ntp.task.gda.pl
/system routerboard settings
set cpu-frequency=auto
/tool mac-server
set allowed-interface-list=LAN
/tool mac-server mac-winbox
set allowed-interface-list=LAN
Question 1: why is you wireguard listen port on the config 13231 whereas you say above it should be 51820 ?
If you're knocking at the wrong door, it makes sense nobody opens ...
Question 2:
peer definition of wireguard: where is endpoint address and port ? It should at least have the own-IP address if the 'other side' does not have a public IP address. It needs an address and a port to listen to.
Once again, please follow the instructions from the documentation. There are a very good base.
https://help.mikrotik.com/docs/display/ROS/WireGuard