Hello everyone!
Is it possible to put car in lfs in neautral with one button?
Or is it possible to make this thing in lfs like the irl cars, like when you press the downshift and the upshift(sequential gearbox) at the same time it puts in neutral?
Thanks for the answers! I hope there isn't any thread with this subject!

I think not - all the commands available for gear selection related to h-gate shifters which work with switches (and thus neutral = no switch pressed).

I don't think classic sequentials are what you are referring to, as you can't both pull and push a sequential stick and expect anything to happen - and I don't know if transmissions with paddleshifters have that sort of feature (holding both paddles = neutral). At least I haven't heard of any such feature in F1 which is a series with paddle controlled semi-auto sequentials.

You can assign a clutch button though which would have the same effect as long as you downshifted all the way to neutral while pressing it.