If you are using 2-Step-Verification and get a "password incorrect" error when you sign in third party application then you can try to create and use an App Password.
Under "Signing in to Google," select App Passwords. You may need to sign in. If you don’t have this option, it might be because:
Tip: Most of the time, you’ll only have to enter an App Password once per app or device, so don’t worry about memorizing it.