Can you share the link to that casino, please. It is interesting to join such bet competition. In my opinion, bets on that should allow which league will firstly return and when. Which league is the first and when it will be return.
I saw advertisement of bookmaker called Parimatch offering such markets. But they don't accept people from my country. Also, Ladbrokes also have it:
https://www.bettingpro.com.au/soccer/sport-return-date-odds