Create Facebook App ID
To use facebook login, you need create facebook app that allow users using facebook API. View this tutorial and follow these steps below to create a facebook app.
Step 1: go to https://developers.facebook.com/apps/
Step 2: Click Add a new app.
Step 3: Choose website.
Step 4: Choose app name, then click “Create new facebook app ID”.
Step 5: Provide contact email, category, then click “Create App ID”.
Step 6: Complete verification code and click “Submit”.
Step 7: Provide your website url. (website that do login process, localhost also works).
When everything is complete. Go to your app dashboard. Get app_id and app_secret.
In App dashboard > Settings, App domains value must matches with Site URL.
If you have questions, don't hesitate, tell us.