Hello Shivam. I'm Greg, here to help you with this.
Try these fixes for I'll give you fixes that work most for MSFS 2020 Game Pass Installation issues, please try them all and report back results.
https://flightsimulator.zendesk.com/hc/en-us/ar...
https://flightsimulator.zendesk.com/hc/en-us/ar...
https://www.avsim.com/forums/topic/608563-cant-...
https://forums.flightsimulator.com/t/installati...
https://www.windowscentral.com/how-fix-microsof...
https://www.engadget.com/microsoft-flight-simul...
https://www.youtube.com/watch?v=mvU-Y49nXfE
If nothing else works then open a ticket with MSFS 2020 Support:
https://flightsimulator.zendesk.com/hc/en-us/ar...
Feel free to ask back any questions. Based on the results you post back I may have other suggestions if necessary.
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