There are a number of ways to link your console account to your Epic Games account. Select the scenario for your situation and follow the instructions in the articles.
To link your accounts via the Epic Games Website:
How do I link a console account to my Epic Games account using the web?
To link your accounts via your console:
How do I link a console account to my Epic Games account using my console?
I’ve only played an Epic game on a console, BUT I don’t know what the email is for my Epic Games account.