cant connect to remote server throght my mikrotik router

I’am a beginner in mikortik. I have MikroTik RouterOS 2.9.27 (172.20.0.4) and i try to set it up by winbox.
So I have to open 54320 and 54321 tcp ports in this router because from behind it i want to connect a remote server, and use a program on it.
I tried to set at firewall that: NAT- Action: dst-nat ,to adressess: 172.20.0.0/24 to ports: 54320-54321, chain: dst-nat dstport: 54320-54321 protocol tcp.
Unfortunatelly it doesnt work. When I check by for example nmap my routers ip it says 54320 and 54320 still close…
Please help me:)