It looks like you have a couple issues here – first, is that the “Em software” app won’t delete itself or at least will re-create itself, correct? If so, can you please launch Brave and go to brave://apps and delete the PWA this way? Then test to see if it reappears again.
For this second part, to my knowledge, this just isn’t the way PWAs work in Chromium-based browsers. When you install a page as an app/PWA, you’re installing the base domain as an app, not a specific page. So any time you go to install the “Em software” app, you’re installing https://emsoftware.com/ not https://emsoftware.com/some/sub/page. You can test this on other sites as well – youtube is an easy one.