Copy pasting key frames

hi all-
searched for this but didn’t find it:
the way to copy and paste key frames, so one can go thru a clip pasting similar frame information to save time creating shapes and to spread more consitent shapes throughout the roto.

i think there’s a way to do it thru the curve editor; no one i’m working with finds it very doable and/or can figure it out.

i also notice in the key frame info panel, where the add key and delete key buttons are, there are copy and paste buttons, but they’re ghosted out>

suggestions? it would cut my time down by x10, and make the work more uniform.