Hi Jerry,
When you create a flight plan in Charts, you can use the Export button, to export it in different formats to the folder of your choice. You will be prompted as to where you want it exported:
Choose the folder you normally load MSFS 2020 plns from. This is likely something like c:\Users\username\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalState\:
Cheers
Ian