You can make use of the Application Change Analysis in order monitor the changes.
To enable the Application Change Analysis for the App Service. You could follow the below steps :
Step 1 : Open the App service resource in the portal.
Step 2 : Access the Diagnose & Solve Problems. Search for Changes. Click on the Application Changes.
Step 3 : Click on the Enable Now
Locate your AppService and toggle the status to ON and click Save
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Moving Forward all the changes will be tracked. You can View the changes by Accessing the "Application Changes" page (AppService -> Diagnose & Solve Problems -> (Search Changes) -> Application Changes )