Well, you can’t just dynamically create multiple apps like that. It sounds like you want an automated process that duplicates a template app, somehow customizes the content for each client and then published as a brand new independent app with it without duplicate data sources. That’s just not how Glide works, so I hope you can understand why this request sounds odd to us. The normal process is to manually design and create an app, and then publish that app. There is no such thing as an automated process that does that.
My suggestion is to manually duplicate and build out each app as needed, publish as needed, and then share the url with whoever needs it. There has to be some sort of manual intervention along the way. Or, you can just use one published app, make all of the client information data driven, such as a detail screen for each client, and then create a deep link to each individual screen in that app for each client. There are several ways to approach it. Here are some useful threads.
Creating a QR code is the easy part. Quickchart has an option where you feed it a specialized url, and what it gives back is a QR image. There are several other third party services that could do the same thing. Build a url in such a way that it is recognized as an image. QR codes are nothing special. Just a coded version of text, such as a url, so as long as you have a url, you can use any service to build a QR code from it.