Player animation help

Hello there again.

I’ve recently put a playermodel in my game and it worked, but when I am empty handed and walk I get the T pose.

So if I’m equiped with nothing, and have my arms next to my body and try to walk/run/crouch walk I get the T pose, but crouching, standing and jumping have the normal animation.
How can I add the empty handed walking/running/crouch walk to the playermodel? And how do I know which animation is the right one? Please help!