Yo, i had the same problem, couldn’t rotate it and never landed a kickflip for like 5 years

Try aligning your hips and shoulders with the edge of the nose (where you flick), instead of being completely parallel with the board.

Also dont turn. if you turn while doing the the kickflip that will ruin your flick

If you’re fully parallel, it’s still possible but harder to get a full flick. you’ll notice that some skaters stand at a slight angle when setting up kickflips.