You can find the app name and owner name from your app URL.
Here are the steps on how to do so:
Navigate to https://appcenter.ms
Navigate to your app
Look at the URL. For example, my personal app has the URL https://appcenter.ms/users/amandachew/apps/DiceOut-01
Owners can be user or org.
The app URL has the general signature of https://appcenter.ms/users/{owner-name}/apps/{app-name} or https://appcenter.ms/orgs/{owner-name}/apps/{app-name} if it is owned by a user or an org respectively.
Example of the URL for an app owned by a user
URL: https://appcenter.ms/users/amandachew/apps/DiceOut-01
The {owner-name} is amandachew and my {app-name} is DiceOut-01.
Example of a app URL owned by an org
URL: https://appcenter.ms/orgs/CrystalGeyser/apps/MacOS-app
The {owner-name} is CrystalGeyser and the {app-name} is MacOS-app.
Happy coding!