How can I copy strokes from one keyframe to another? How can I copy selected stroke from one keyframe to another? I don't want to redraw it manually or duplicate keyframe, because it overlays current keyframe, I just need one particular stroke to be copied.
You can copy and paste ctrl-c ctrl-v or use copy paste from the grease pencil menu. Go to the frame you want to grab the stroke from.. then copy.. go to the other keyframe.. paste.. and adjust as needed from there. (blender 2.81)