How can I launch my Windows 10 app from my website (using JavaScript?)

I am developing a public Windows 10 app that should also be launched using a specific URL (https://app.scancircle.com) from my website and emails.

I partially managed to do that using the info on https://docs.microsoft.com/en-us/windows/uwp/launch-resume/web-to-app-linking. This works great when the URL is activated from an email or a command prompt, but not from within a web browser.

It should be possible as it works for MS Teams and Skype invitations (see e.g. https://join.skype.com/bYUOZtOCL4pi), but I cannot figure out how they managed to do it.

Anyone any suggestions?

Some further info:

1. It should work in Windows 10 with any modern web browser and without any specific settings or add-ons (unless that can easily be done during the installation of the app);
2. If the app is not installed, the specified URL should be opened so I cannot use a specific URL protocol like scancircle://
3. On my computer, my app is listed under Settings > Apps > Apps for websites (so that worked);
4. The app is not yet listed in the Microsoft Store (working on that);
5. The suggested JSON file has been installed in the root directory (but does not seem to be used for local installations);
6. I am converting an existing program to a Windows 10 app in VisualStudio 2019 using the info on https://docs.microsoft.com/en-us/windows/msix/desktop/desktop-to-uwp-packaging-dot-net.