How to remove "Planner"/"Inbox" columns on Trello board?

[Stephanie Grace Pepper]

I originally opted in to use the Planner feature for Trello.  I do not like how it takes up 2/3rds of my Trello Board.  I want to remove it.  Google AI says to go to "Show Menu" in the top right corner to return to "Default" board.  I cannot locate this menu feature.  Any ideas how to get rid of planner and the inbox column to the left of it?

Thanks

[Gaurav Kataria · Accepted solution]

You can resize the panels by dragging the boundary, and also open/close them by clicking on the buttons in the bottom island. See animation below:

[Stephanie Grace Pepper]

Excellent Gaurav!  I had tried the options across the bottom.  Did not know about dragging the boundary.  That did it. Thank you!