Hi Vince,
Pls follow "Method 2" ("Download the Microsoft Store installer") in the Reinstall Microsoft Store article.
After you download the Msixbundle and Appx packages, you can double-click to install them. Install the Appx (dependency packages) first, and then run the Msixbundle file.
If you can't install the packages interactively, you can install them using the Add-AppxPackage PowerShell command.