How to transfer values from radio buttons?

Hey guys, I’m new here and I want to create some kind of survey. In the end, two opposites (items) are always juxtaposed and you should choose your tendency to which you feel you belong more.
My idea was to use RadioButtons (also for aesthetic reasons), but that doesn’t work. I saw here that there is already a tutorial for a Net Promoter Score, but unfortunately I don’t have a Field Type “List of numbers” to choose from.
There are three databases, once the participant, which contains only the ID, because I want to work without login, the item database. It contains the name of the items and the average result of the individual values of the respective items and the result database. This contains the participant ID, the item name and the selected value (numbers).

Would be nice if someone could send me a reference to shimmy along.

Many thanks in advance and best regards

Liz