Make sure you are an assigned user to the app (you can check the settings here as well under Members):
- Sign in to the Azure portal as the global administrator for your directory.
- Select Azure Active Directory.
- Select Enterprise applications.
- The Enterprise applications - All applications blade opens. Under Application Type, select Enterprise Applications, if it isn't already selected. Search for the application you want to hide, and click the application.
- The application's overview opens. Click Properties.
- For the Visible to users? question, click Yes. Click Save.