Please see https://www.shamimsplugins.com/docs/front-end-pm-pro/getting-started-2/email-beautify/
Default basic template is shifted with this plugin. If you want to create your own you can follow https://www.shamimsplugins.com/docs/front-end-pm-pro/customization-front-end-pm-pro/create-own-email-template/
You can see templates/emails/default.php to get the default email template. You can use this as a starting point.