I want to increase a value in the collection when a checkbox is checked and submitted in a form

This seems like a simple question, but I cant seem to find out how to do it.
I want to increase a value in the collection on a check box being checked on the submitting of a form. I don’t see that option. How do I go about doing this?

My form looks like this -

Thank you

Checkboxes are true/false values.

So on the action itself, you have an action that IF that property is true, it will update the collection according to your needs.