How can I set pose position to rest position?

Please help! When I edit a keyframe by doing alt+r and alt+g it resets my bones to my rest postion (which is what I want), but when I drag my timeline cursur around suddenly the keyframe reverts to a different pose position!!! How can I change the pose (permanently) to the rest position?

I’m SUPER new to Blender btw

Two things: Once you’ve set a keyframe, it doesn’t matter what your rest pose/pose position is, it will show that keyframe and there are a variety of options under the apply menu.