How to configure VLANs on the switch?

Hello everyone,
I would need your help to configure two VLANs on the switch.
I know that there are many guides online but absurdly they all seem to report more complex cases than mine and trying to take inspiration from these I was unable to make my system work which, I am sure, requires a very simple configuration.

Introduction
The devices involved in the system are:

• AP Zyxel NWA130BE
• Switch Zyxel XMG1915-10E
• Firewall/Router pfSense

I have correctly configured two VLANs on the firewall/Router pfSense with TAG 20 and 50. The Firewall is also responsible for assigning the IP addresses for the participants to both VLANs.

I have also correctly configured two VLANs on the AP with the same TAGs, assigned to two different SSIDs.

(I'm using the term "correctly" because the system has already worked perfectly in the past, so I know for sure that the configurations on the Firewall and AP are correct)

I would need to configure the switch to pass the traffic of the two VLANs through the ports involved. The VLANs will be used exclusively by devices connected in WiFi on the two SSIDs.

(I had already set up the switch in the past, but following a power outage the switch lost its settings and I'm having difficulty setting it up again)

These are the connections to the switch:

• Firewall/Router on port 1
• AP on port 8

So, in the Web UI in the SWITCHING/VLAN/VLAN "Setup Static" VLAN menu, I create VLAN 20 and VLAN 50 and so far everything is ok, but how do I set up the ports?

In both VLANs I have to involve ports 1 and 8 I suppose, but how are they? Tagged, Untagged, Normal, Fixed? And how should I set the ports not involved?
Do I also need to set something in the SWITCHING/VLAN/VLAN "VLAN Port Setting" menu?

Thank you for your help