Board Rush is a limited-time event in Monopoly Go! where completing your Board while the event is active earns you extra rewards. You can complete your Board by completing all Landmarks on your current Board.

Q: What should I do if I completed my Board and didn't get my reward? 
A: The rewards may arrive with a slight delay, so restarting your app should fix the issue.
If the issue persists, contact customer support through the game's help menu.