The ‘Send Confirmation Email’ action is used to confirm that a user’s email address is valid and that they can access it (for example when they first sign up to your app).
I’m not sure if that’s what you’re trying to do here, but I don’t think it is…
If you’re trying to send a payment confirmation upon receipt of payment (which I think is what you’re trying to do), there are a few ways to do it, but I’d go about that in the following way…
Create a backend workflow with a single action to send an email to the user (personally I use Sendgrid for all our emails, via the API connector - but however your app is configured to send emails, such as if you’re using a plugin, then just use that).
I’d recommend triggering the workflow via a webhook from Stripe (or whatever payment processor you use) rather than using anything in the browser, for example a pageload workflow on a thank you page, or in a popup, and certainly not on a button click - otherwise there’s a good chance you’ll end up sending confirmation emails to people who haven’t paid, or who’s payments have been declined.