Why don't I see any prompts to clip after scoring a goal in Rocket League?

Make sure you are playing on a supported console. Clipping with Postparty in Rocket League is currently only supported on PC, PlayStation, and Xbox.

Also, make sure you have logged into the Postparty app with the same account you use to play Rocket League. When you first log in to the Postparty app, it should show your Epic username in the header, and your console usernames (if you have any) in a window at the top of your Library. You can double-check in game by looking for clipping-specific keys in the Key binds menu.