Manjaro doesn't use my graphics card

2 Days ago I have bought a ASUS TUF Laptop with a Ryzen 7 4800H and a RTX 2060, I have installed manjaro and chose nonfree drivers, when I have started to play some games on steam I have noticed that they are slow and it turns out manjaro isn’t using my GPU how can I fix it?

//EDIT:

In the game Properties on Steam (right click the game, then click Properties…), modify the Launch Options literally to this:

prime-run %command%

see option prime command

It seems like it’s already installed

What ?

the prime driver is already instaled on manjaro

Yes then follow the rest.