How can I verified if a email adress is already use by a provider (google or facebook)?

In my web app I use login firebase (google and facebook) but I would like prevent user if he's email adress is alreasy use by google or facebook, for example if my user would like connect with google, his email adress is user@example.com and after he would like to connect but with facebook and his email adress for facebook is the same (user@example.com). How I can verified if the email adress is already exist?