Order form

I have a Google Sheet document.

I need to do two things:

1. I have four columns that are selected by checkbox. I want to make it so that only one checkbox can be checked at a time. ie if one column is ticked and then another is clicked the first column is unselected.

2. I want to have a message box display a message if data is input in a column when one of my checkbox columns is not selected.

I have ChatGPT Code written for both but could not work out how to get Google Sheets to apply the App Script.