how to view permanent preview of e-mail sent after the purchase when developing

[Emma Iana]

I want to change the appearance of the e-mail that is sent after the purchase.
I know what files to change, I know how to change.

What I don't know is how to call up a permanent preview of the view of such an e-mail with data to keep an eye on the changes being made.

What is the correct approach for a developer to make such changes?
Cheers

[Jumbo!]

You might consider using VP Email Manager: https://www.virtueplanet.com/extensions/vp-email-manager.