Connect direct 2 routers VLAN

[Antibiotic]

Hi, please explain is it possible to use VLAN directly between 2 routers without any switch. If yes how to connect?
First router pfSense
Second router with VLAN support
This is second router options:

Have additional interface on pfSesne. The primary idea to connect as VLAN AP wireless point. Should be better use interface as VLAN on pfSense? I mean without assigning physical interface?

[JKnott]

@Antibiotic

Yes, you can have VLANs without a switch. Just connect the 2 devices with a cable and you can put what ever VLANs you want on it, though I'm not sure why you'd do that.