How to choose one button of 6 button?

Hello everyone!

so, I made 6 buttons and 1 button that can be typed.
Can I only choose 1 button from the seven buttons?
So, if I click on 1 button, then 1 button that can be typed cannot be selected either

Please help me, I don’t understand how to make it

This is the file:
Forum.rp (269.2 KB)