Do you use Ultimate Member? The Ultimate Member integration allows you to automatically send a welcome email to your new users. You can integrate your account with Studiocart by installing the plugin on your WordPress site.

How To Integrate Ultimate Member With Studiocart

Get started by Installing and Activating the Ultimate Member Plugin on your WordPress site. 
Then head over to your WordPress Dashboard, select Studiocart > Settings.  

Select the Integrations tab and turn on the button to enable Ultimate Member. Scroll to the bottom of the Integrations window and select Save Settings.