I'm asking if there's a method to send an email automatically from my app in Android Studio without opening Gmail with "Intent.ACTION_SEND" and without turning on "less secure apps" on Google account settings. My app has already a Google sign-in method connected with Firebase Project.
When it comes to Firebase and sending emails to users, the best option that you have is to use Trigger Email Extension from Firebase. There is no need to open your Gmail account in order to send an email. To implement the extension please follow the steps that are explained in the following article: