This website. You can paste any URL from the Microsoft Store (or enter the ProductID) and you can then download the msixbundle from there directly. This is great if you're like me and want the Microsoft Store uninstalled completely. This doesn't really have a use on LTSC versions, but if you're on Windows 11 (and more modern versions of 10), Notepad and Paint come from the Microsoft Store by default. You can use it to get the latest versions, or for any app really. Of course, it won't automatically update and it's up to you to do it yourself.
9msmlrh6lzf3 ProductID for Notepad
9pcfs5b6t72h ProductID for Paint
You can then open PowerShell and run this to install it:
Add-AppxPackage C:/path/to/msixbundle
Edit: You can also double click on it to install it with a fancy GUI on Windows 11 now. Pretty sure that's new as I don't recall being able to do this on 10.
Just a neat little website I found in case anyone needs it