Login Via FB Leads To Create A New Account Instead Of Loging In

Hy There So When A User For Example in my case sign up with email -->[email protected] And Confirm The Email Address So Then If I Logout And MAke sure that the account associated with [email protected] is logged in on facebook and on apitest.io when i click on sign in via FB it leads me to Registration Page With FB Details Entered Within It. So Basically What Usually Happens Is When For Example an account is made from [email protected] and user sign in with fb he must be logged in no matter what. You Can Even Check This Same Thing on imgur.com And Its Usually The Most Efficient Thing And Found Common On Any Web App. Thanks For More Info Lemme Know