Redirect On "Registration Completed" page

Hello,
On the "Registration Completed" page would it be possible to add a button to direct the registrant to the payment page? We are a government entity and we have to use a certain company for payment. I would like them to click a button to go there. Or, is it possible to automatically redirect them to the payment company when they click on "Process Registration" on the page before the "Registration Completed" page?
Thanks!!

I think I can do it in the "Email & Messages" section. Thanks

Yes Jim, that's the correct solution.

Tuan