Can't use it / doesn't show up (logged in or anonymous)

Edit

I just found out, that I can install it by clicking in the Chrome desktop browser when I'm logged in.
But I can't do so when I'm in an incognito window.

So this isn't a bug in this module perhaps, but just how Chrome works? Please compare to any other PWA, see Demos at https://www.pwabuilder.com/
("Try a demo url")

Seems as if you're right - I'm on Chromium with KDE / Ubuntu underneath. Other PWAs seem to be working in the same way.

How about the link in the footer?

Works as designed without a link?
Do you have an example of how it should look like?
Nobody is using the block, page visitors need to install it via the address bar feature from the browser?

The same problem. The button is missing in Chrome, it works fine in Microsoft Edge.