Hello there @ManishPaul09!
Welcome to UE! And thank you for providing the log extract. There are calls to a few credentials/authentication conflicts, please check the following:
- Make sure you are properly logged in to the Unreal platform
- If you are working behind a VPN, try disabling it and testing packing again
- Same with your firewall, check for any rulings that could be affecting your connection with Unreal
- Finally, please update both your UE and Windows to their latest version
There was a reported issue with this error affecting UE 5.3, it was fixed for 5.4, as seen in the following reports, here and here.