Not all of these mini PCs have a wifi card in them even if they have the antennas for it. You might start by opening it to check whether the wifi antennas are connected, or whether you need to add a WiFi card.
I think OPNsense would do what you’re looking for. I use it on a mini PC as my router, and it’s great, but I have not used it for WiFi (I run a separate access point). The limitation is WiFi hardware support. You will need to make sure your mini PC’s WiFi card has a driver in FreeBSD. Intel hardware is often a better bet than Realtek etc.
Not all of these mini PCs have a wifi card in them even if they have the antennas for it. You might start by opening it to check whether the wifi antennas are connected, or whether you need to add a WiFi card.
I think OPNsense would do what you’re looking for. I use it on a mini PC as my router, and it’s great, but I have not used it for WiFi (I run a separate access point). The limitation is WiFi hardware support. You will need to make sure your mini PC’s WiFi card has a driver in FreeBSD. Intel hardware is often a better bet than Realtek etc.
https://docs.opnsense.org/manual/how-tos/interface_wireless_internal.html