Unable to configure my gmail account

I have been trying to configure postie by updating my gmail server details. I have tried both IMAP-SSL and POP3-SSL but have failed.

I have used the exact same configuration as mentioned at:
https://postieplugin.com/postie-gmail/

But when I click on the button, “Run postie(debug)” after saving the details I am getting a 500 internal server error saying,
“Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, [email protected] and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.”

Kindly help me resolve this problem.

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