Need help with creating a variant where my customer can write in custom info; like a badge number

Site URL: https://www.corporatemark.com

I am not good at the new updated Squarespace. I need to add a custom variant where my customer can write in their badge number and I have looked everywhere. The old system was so easy......any help would be so appreciated...

I was able to use the variant for badge locations but could not find where I can add a place for the purchaser to add a custom badge number...urg!!!

Thank you so much for your help!!!!!!!!!