Hello, can the hAP ac² act as a router instead of an access point? I want it to act as a DHCP server and use firewall nat rules.
Yes it can
any mikrotik running RouterOS can act as router with firewall, NAT, DHCP, Queues, VPN, etc etc..
That is true for every model except CSS range (which feature SwOS)
hAP ac2 actually comes with factory default setting as router+ap. Your WAN will be predefined on eth1 while wifi and eth2-eth5 will work as LAN. You can of course reconfigure it in any way you can imagine.
It doesn’t need to act, because it already is a router out of the box (and has some firewall and NAT rules pre-configured already, for your convenience).
Exactly what it is designed for