XLR Mains at Mic or Line Level?

[DatScrubBoi]

I'm not a complete newbie with audio gear, but I haven't had my hands on many mixers.
I'm looking at this one for a very specific use case with alot of digital routing:
https://www.sweetwater.com/store/detail/XR12--behringer-by-air-xr12-tablet-controlled-digital-mixer

Basically I'm going to use it to split one XLR mic to two different computers, and also have the audio from each computer feeding into each other. I can feed the AUX outs to the 3.5mm line-in's of my two PC's motherboards and digitally rout the audio to each other on a bus, and I want to have the mic audio routed to those two XLR mains outputs to be sent to both computers. That's all pretty easy to do on these Behringer digital mixers.
However, I need to know if those XLR mains outs are at line level and should be adapted to the 3.5mm mic-in on the motherboard, or if they're mic level and should be used with two of my USB audio interfaces.

I know the board pre-amplifies the mics, but is there any way to tell what I'm looking for? From those that know more than me, what's my solution?

(Also, I know I could just feed the audio from each computer to each other, but I also want to be able to feed all that into my headphones mixed just right and have the flexibility to add other mics and aux inputs in the future)

[kasugatei]

Mixer outputs are line level in most of the cases.