After you make a purchase from WPDeveloper, be it BetterDocs, NotificationX, Essential Addons or any other plugin and theme, you will immediately receive an Email Receipt. That email will contain all the information about your purchase.
If for any reason you can't find your Email Receipt from WPDeveloper, you can always see details about your purchase history from your WPDeveloper account. From there you can also download installation file for our plugins and themes.
Use this URL to land on your Account Page. https://wpdeveloper.net/account/. You will see five tabs on your My Accounts Page.
From the Downloads Tab, you can see a list of the items you have purchased from our Website.
No matter which WordPress Plugin and Theme you are using from the WPDeveloper team, be it NotificationX or BetterDocs, you can see the purchase history for all of them from your WPDeveloper Account.
If you face any further difficulties finding your license key, here is a quick Doc on how to seek Support from the WPDeveloper Team.