coupon image generated, mails not being sent

Hi!

I have a problem with sellable gift certificates.

J! 5.2.2

AwoCoupon 4.0.1.4

Php 8.3

Everything is configured as it should be.
Buying the coupon everything is working until the redirect to the site.

This apperas with "Template error page message : Unknown error ..."

Refreshing the site I get

"Order already captured.If 'intent=CAPTURE' only one capture per order is allowed."

The coupon image is obviousely generated and can be found in the tmp folder - but the mail isn't sent to the customer :(

What can it be?

Mailconfig within Joomla is complete and working using SMTP.

Hello,

Try this, go to awocoupon > configuration > gift certificate tab, and activate 'Debug'.  Then try another order which should send the email.  Refresh that page, and is there anything in the text field ""output"?  If so, what?