On your Android phone, head to “Settings,” then scroll down and tap Google > All services. Select "Autofill," then "Autofill with Google,” and make sure "Use Autofill with Google" is turned on. After that, whenever you create a new account using a browser or on an app, you’ll have the opportunity to choose a safe, custom-made password.
When creating an account, tap the password creation field, select the key icon, and choose “Generate password and save to your Google account.” Complete your username, and your password will be auto-saved.