Struggling to find a way to make Radio Buttons a required field in my form

Community Beginner ,

I have Adobe InDesign 2020 and creating some forms with radio buttons. Used 022 from the 'Sample Buttons and Forms' menu. Successfully added a fourth box to the set of three and grouped them. But cant seem to find a way to make these grouped Radio Buttons a required field within my form. Is it possible?

Had the same issue with 'Check Boxes' so changed the question and answer to a format that worked with a 'Combo Box' instead.

Don't have that option with this particuar question this time.