Generate OAthu Credentials for email

You are required to use Gmail for sending emails to your user. You will need to generate credentials that will then be needed on the .env file.

1. Go to Google Dev Console.
2. Enable Gmail API.
3. Create the project, I named mine MangaDB.
4. Click Create credentials and select OAuth Client credentials.
5. Give it a name, use https://developers.google.com/oauthplayground for the Authorized redirect URIs and copy the client id and secret.
6. Go to OAuth 2.0 Playground and on the gear on the top right:
   • Tick Use your own OAuth credentials
   • Provide your credentials
   • Use https://mail.google.com
   • Copy your refresh token to .env file.