I'm creating a donation form, and before the user submits the form I would like to display a line just above the submit button that shows something like this: "I'm helping EonA with a donation of € ** per **, where both ** are values taken from radio buttons/fields/values in this form. How can I do this? I've tried paragraph with [keys/ID's], but until now with no success.
I know how to use get param = name to pre fill form fields, but these fields are always visible so they can be changed by whoever has the link and visits the form. I want to sent participants a unique link with which they can visit the page with the form and where their name and email address are already filled in and can't be changed. How could I hide these variables or is there another way to prevent people form using the form twice or altering name and email address.