hello, I have tested PWA app in Chrome, Opere, Firefox browser. The PWA app works well in Chrome. and the Opera and Firefox browsers do not show a tooltip to install the PWA app. It can only be added manually through the browser settings, and it does not always work. I've only been able to install the app on the home screen once out of many attempts.

I think you can only neet criteria to show "Add to home page" button, but how it is generated and when only depends on browser (and maybe user preference and history of showing such button).

You cannot force it to be shown.

Please tell me, is it possible to make a separate link, install it, for example, in the footer of the site, following which the user will install the application on his main screen?

Probably yes, we have not been discovering this, as if browser supports pwa, then will at least install button in options.

This seems to be that:
https://www.amitmerchant.com/adding-custom-install-button-in-progressive-web-apps/