Single MSIX Package for Different Environments

Abhi211 The request sounds more complicated than can be explained here, but I can provide an overview of your options. 

One way is to use the free PsfTooling during the packaging process.  While in the installation phase of the Microsoft MSIX Packaging Tool you would install the program and copy down any scripts, and then launch PsfTooling.  The GUI provides the ability to define the script to be run, including any arguments.  Check PSFLauncher documentationHome · TimMangan/MSIX-PackageSupportFramework Wiki (github.com)  for variables to use in the arguments that evaluate to the Package Folder and Redirected Package Folder that you'll probably need.  In the GUI you'd just click the checkbox to add in the MfrFixup while there.  There is some text that will be displayed when you add the MfrFixup in ILV-aware more that must be copied to your clipboard.  After you close PsfTooling and return to the Microsoft packager, you complete the packaging process short of saving the package.  You must then export and edit the AppXManifest file to copy that text into the manifest as shown in the XML comments that you copied.

Alternatively, TMEditX (a licensed tool) can be used to perform these actions on a post-packaging editing session.  The GUIs for the two are very similar for defining the script and enabling MFrFixup, but TMEditX will fix up the AppXManifest for you automatically.