Step 1 | Connect with Stripe
First, make sure your ResDiary is linked with stripe.
See the following Articles:
Step 2 | Stripe Settings
Step 3 | Payment Settings
1) Go to Settings > New Booking Process Payment Settings
2) Green Light (enable) ResDiary Voucher (note, ResDiary Voucher NOT Voucher)
Step 4 | Test!
Always best to see how it works from a customer point-of-view
Go to Promote > Front-End Vouchers
Go through the process (without purchasing) to see if all works well.
If you get as far as Card details - all is well!
If you get an error 500 at any point - make sure that Stripe is enabled.