When I’m in the game I can drive with auto clutch. As soon as I switch to manual the clutch doesn’t do anything and the car won’t even go in gear. Can someone help me figure out what the problem is. I have a Logitech g920 and the wheel and pedals work perfectly in any other game

Hey there and welcome to LFS!

This link on the LFS Manual is useful to set up the wheel.

First thing to do is to check the settings for the clutch:
Options > Controls

Under clutch, check if it set to "axis" or "button".

Once its set to axis, click on the tab for "axes / FF".

This GIF from LFS manual shows how to assign axes for each function.

Have a look at the other pages on the LFS Manual (wiki) as there are tons of useful info.

Hope that helps to sort the clutch issue!