@abmex , I got my first 2 Godox TT350F flashes a few days ago - really cool little strobes! And yes, I can confirm that you can use one as a trigger only, without firing.
First, set your master (on-camera) by pressing and holding the SYNC button until the antenna icon starts flashing. Turn the wheel until M is displayed next to the antenna icon. Cycle through the flash modes (TTL, Manual, Multi, Off) by clicking MODE. Set it to off.
Setup your secondary flash as slave by pressing and holding the SYNC button until the antenna icon starts flashing, then turn the wheel until S is displayed next to the antenna icon.
Check this demo out, setup master/slave: ~1:00 in, turn off master to use only as trigger: ~1:40 and ~3:00 in: https://www.youtube.com/watch?v=tBj47_8ci9U
Good luck! 📸