Creating new Wifi with FortiAP - Vlan yes or no

Hi,

I have to configure new FortiAPs changing from a configuration with different Ubiquities. Right now they have like 2 SSIDs and they are in different Vlans. Problem is that the FW is in the warehouse and they pass connection from a Cisco Switch to another Switch via VLan.

I told the provider who manages the switch that I need ACCESS ports with VLan whatever he wants to connect the FG60F directly to port X on the Cisco Switch and also to connect my new FortiSwitch in port X on the other Switch. From there I have direct connections from the PoE FortiSwitch to the 5 FortiAPs.

Now I am not sure what to tell them, do I need the specific VLan also on my new Interface Port 4 in the FG60 which I name FortiAP Zone? I understand that bothe Wifis will have automatically their VLan and network, etc. So it should work having the access connection on both switches, right?

Something else I have to consider?

Thanks!