On May 30th, 2022 ​​Google will no longer support the use of third-party apps or devices which ask you to sign in to your Google Account using only your username and password.

Solution for customers who use Gmail accounts in their application: Sign In with App Password.

Add App Password to Google Account: https://support.google.com/accounts/answer/185833

Once the App Password is obtained, simply replace the current Gmail Account password in your PLC application with the App Password.