ClearForms offers a variety of ways to collect and use numeric data. The following ClearForms field types result in a numeric value:
Number (no decimal)
Number (with decimal)
Multiple choice (with formula values added)
But those field names won't show up when you select "Fixed" payment option when setting up a payment step.
Here's a tip:
To use the results of a number field as a payment you can set up a Formula that's just the Field Name x 1. To create a new formula select Power Ups from the Workflow edit view and then select New Formula. Create a simple formula by selecting the number field you want to use from the right side of the Formula builder and add "x 1" to it. By multiplying the field value by 1 you won't change the number - but once you add a name to the Formula and save it you'll be able to use it in a payment step. Here's a video overview of how it works:
Thanks for creating these formulas and working around the limitations of our software! It's on our feature development roadmap to allow fields to be directly added as payment values. Stay tuned!