How to uninstall an App from self service app?

Use this https://github.com/ScottEKendall/JAMF-Pro-Scripts/tree/main/AppDelete or https://github.com/erikstam/uninstaller

If you've installed an app from Self Service and only see a "Reinstall" option, it means there isn't a built-in uninstall button provided. The simplest way to uninstall most macOS apps is to open your Applications folder in Finder, drag the app's icon to the Trash, and then empty the Trash. For a more thorough removal that includes upsers com associated preference files and caches, you can check in ~/Library/Application Support/, ~/Library/Caches/, and ~/Library/Preferences/ for folders or files related to the app and delete them, or use a third-party uninstaller like AppCleaner. If your Mac is managed by an IT department, they might have specific procedures, so it's always an option to contact them if you encounter issues. 

When an app installed through Self Service only shows the "Reinstall" button and doesn't offer an "Uninstall" option, it usually means the app was packaged without an uninstallation script or policy. In such cases, Self Service doesn’t provide a built-in way to remove the app.

Jamf Deploys the source files you give it. You give Jamf a Package, it executes that Package and that Package does what ever it was designed to do. The “Install, and “Reinstall” buttons are customizable and those are just the defaults Jamf has programmed in to the UX.

If you want Jamf to uninstall something, you need to make a Package or Script that uninstalls the thing and a second Policy for the uninstaller. Then you change the button to say “Uninstall”. There are some things you can do with Indexing DMG’s to allow Jamf to remove what the DMG placed on the device, but this is very niche as almost no one uses DMG’s anymore.

My suggestion is to using something like Suspicious Package to analyze the Package you are Deploying. Reverse engineer the Package and make an uninstaller, also search the disk for changes the Package makes after it runs its scripts. Of course if the Publisher makes an uninstall Script or Package, use that.