I have some experience with this, you can use javascript on the https:// meeting link to detect if the app protocol (zoom:// or whatever) exists. If the app protocol exists then go straight to the app protocol link. If it doesn’t then prompt the user to download and install Zoom. The JS is a bit messy and requires a few different approaches but it works on all popular browsers on Windows and Mac (Linux support wasn’t needed, so not sure).

Of course, the browser will pop up a confirmation dialog to ask if you want to open the Zoom app but this is a feature not a bug.