Please note that you can only submit one Showcase in each city you've unlocked. So if you have unlocked three cities, you can have at most three Showcases running at any particular time (and so on). Once other players have finished voting on a specific Showcase and you've collected your results, then you will be able to use a Key in that particular city for a new Showcase.
Why can't I submit a Showcase when I have plenty of Keys available to use?
Last Updated: 1008d