Hi Peter,
PowerClient is client/server architecture, so no... your app is not at all running on the Web server. The Web server is really just acting as a file server for the user to download the app from (including subsequent automatic updates) to their local machine and execute still in client/server mode. If you want to deploy over the Internet/Cloud, you should look at PowerServer 2021 instead.
Your link is incorrect. You should never link to the .EXE directly. You need to link to either the "auto.html" or "manual.html" page depending on what mode you want to run the Cloud App Launcher as. Please read the "Deployment tab" section of the documentation: https://docs.appeon.com/pb2019r3/pbug/ch07s03.html#defining_an_ica_project
You can customize the Cloud App Launcher where it caches your app on the user's machine, and by default it is the roaming folder: https://docs.appeon.com/pb2019r3/pbug/ch07s03.html#uploading_the_app_launcher_and_runtime_files
But to achieve what you outlined of multiple apps (UAT, PROD, etc.) this is NOT the right way to do it because the Cloud App Launcher is universal for all apps rather than specific to one of your apps.
You can make multiple PowerClient project objects and deploy to unique folders on the Web server (e.g. AppNamePROD, AppNameQA, etc.) and the URLs you give the user would be matching accordingly.
If the app is exactly same and the difference is what DB you connect to, I think a better way to do this is have a single .INI file that has all the various DB settings and you dynamically switch based on what CommandParm argument you pass to the app. You can pass CommandParm in the URL as follows, which is also explained in the documentation: "<server>/<dedicated folder>/manual.httml?arg=XXXX".
I recommend you carefully read the entire documentation from start to finish about PowerClient.
Best regards,
Armeen
Cheers,
Peter