How to grant permission to external application to use Gmail account?
Step1: Login with your Gmail Account.

Step2: Click on My Account.

Step3: Click on Device activity & notification.

Step4: Enable Allow less secure apps.


Step5: How to Unlock Captcha.
Visit below Link to unlock Captcha :
https://accounts.google.com/DisplayUnlockCaptcha
Press Continue to allow Gmail.
Visit below Link to unlock Captcha :
https://accounts.google.com/DisplayUnlockCaptcha
Press Continue to allow Gmail.


Step6: At last Sign out Account.


