Boosteroid supports only the first method of Epic authorization where you need to fill in your email address and password. If you have your Epic account registered either on Facebook, Xbox, Playstation, Nintendo, or Steam you should get a password for your Epic account.
Note: if you cannot put the @ symbol, please choose the English/American keyboard layout and press the combination of Shift + 2
Even if you used to automatically log in to Epic by means of Facebook, Playstation, etc., you should get a password for your account for security reasons.
Click Sign In with Epic Games.
Click Forgot Your Password.
Write down the email address associated with your Epic account.
Click Send Email.
Create a password for your account.
Choose Sign In with Epic Games again.
Write down your email address and the new password.