Avastar. Non T-Pose Rigging

[Sunbleached]

Hello! I am trying to rig a non T-pose character. Its in an "I"-pose actually, arms are down, legs together. So I rig it, everything is fine, but how do I get it back to T-pose before I upload it? Alt+R dont work.

And another thing. It seems bones are somehow locked, they dont move 360 degrees, its fine but still curious how to disable it.

Any help please?

[Sunbleached]

Well, I watched this video, seems clear.

https://avastar.guru/avastar-2/reference/rig-to-any-pose/