Wordpress auth0 plug-in, There is a user with the same email

new here, appreciate your help
initial setup seems easy and straight-forward. I can log in with google sign in, but got an error (There is a user with the same email) with facebook sign in (same email address). I think there should be a checkbox “link same email addresses for accounts” somewhere, but just can’t find it.

I did look All of a sudden: "There was a problem with your log in: There is a user with the same email.", if I run mysql query “SELECT * FROM bitnami_wordpress.wp_usermeta where meta_key like ‘%auth0%’”, meta_value has values (google-oauth2).

Basically, no matter which social provider I choose, I want to be signed into wordpress with only email address.