I can't access the game, it says : check account !
You should enter a support ticket with Game Insight. You can do it on their website: https://www.game-insight.com/en/support/form?lang=en
You will need to know your support ID. If you are on an Apple device, you can get it like this:
Open Settings on your device → scroll down to see the Apps section in the left column → choose the Big Business Deluxe game to see your Support id in the app info in the right column.
I can't see my ID, because I can't enter in the game !
I'm windows 10 on PC
Sorry, no idea how to do that on Windows 10. I play on iPad. Perhaps a search of the Game Insight support website would reveal some way of doing it. Maybe this?