Change Back button function to go to static URL

Very simple I imagine.

I have an RSVP form, on page one of the form I want it to say
“Name”
“are you attending”

with 2 buttons, [yes] [no]

If no is hit, I want the form to go to a specified URL, if yes, then to the next form page…

Any one?

https://wordpress.org/plugins/contact-form-7-multi-step-module/