The approach I’d recommend trying first is to have a script detect your radio button change, and then immediately update your form’s redirect URL appropriately. Then the form submit will happen naturally ( webflow’s handler, or logic’s ) and your form should naturally redirect to your designated URL after.
I haven’t tested this however. If Webflow doesn’t detect the URL change after their scripts are loaded then the plan B approach is to do the redirect manually when submit is clicked.
We had a similar problem we wanted to solve except our solution required a select field. If anyone needs this script updated to work with radio buttons, please let me know!