Ok i finally found your website URL ****r.media and it doesn't have favicon component configured. How did you actually configured it? did you just installed it? not configured? you need to configure that in admin panel -> configure -> Favicons

Obtain keys, upload icon , generated and then install from the same page.

Another thing is you never installed this component it at all didn't found any XML manifest file ***.media/components/Favicons/ossn_com.xml and ***..media/components/ServiceWorker/ossn_com.xml

So no idea how it supposed to work without installing these and configuring it. It won't work its own.

@Doug the question is still not answered by you we need your website url to check why its not working.

I have no idea who told you to look dozen of files as its simple process to configure the components.

We tried to get questions answered for the past 2 months, but your site never approved our registration

We submitted questions to the OpenTeknic (6 times) but were unable to resolve the PWA not working.

We received answers like this:

"If you installed and configured both components including favicon everything happens itself."

In our case, we tried dozens of file and folder locations. We never received information on where to install the folders and files - or what needed to be configured.

We were also told no examples of working sites utilizing the PWA could be provided since it was a 3rd party component.

We are racing right now and don't have a lot of time to look at the code. We realize that people are busy and that this project is not a priority for many involved. We will look at how to fix it, or go back to our older WP code when the racing season is over in November.

Thank you 

we have tried everything

Dough,
I don't think that anyone would spend a thought on what may be that "everything".
We need details we can investigate. So, please provide at least the url of your site and the brand, os, and browser of the device you were trying to install the WebApp on.
See https://www.opensource-socialnetwork.org/wiki/view/1101/how-to-report-a-bug-error-issue

Hello Arsalan, we have tried
everything contained in that link, but we still can't get anything to happen. The developer will not respond to any inquiry and we are not sure if any paths need to be updated to make the app work. We will continue to look at the code to find our error. Thank you.

Doug by using https://www.opensource-socialnetwork.org/wiki/view/5958/how-to-enable-pwa-for-ossn

Dominik L , I have not been able to get the PWA to work on our site. What code, or paths did you have to alter for yours to start functioning?.... Thank you.

Yes some browsers allows that.