Follow the steps below to select a custom App Selector Image for your application:
Open the User Interface configuration (Administration > Applications > App Designer > User Interface > Header):
Click Choose File under App Selector Image:
An explorer window appears. Locate and select an image to use, then click Open.
The User Interface screen appears with the selected file listed next to the Choose File button. Click Save to save the changes.
The screen refreshes and the newly selected file appears on the configuration screen.