@Amar-Azure-Practice How are you defining the app settings now ?
In case of ARM template, you can use parameterized value for the app settings using resource type config-appsettings in the script.
I am sharing couple of relevant reference link as how to parameterize the app settings in the script :
https://blogs.perficient.com/2016/03/17/azure-arm-template-define-web-app-application-settings/
https://microsoft.github.io/AzureTipsAndTricks/blog/tip163.html
https://kalcik.net/2019/11/21/merge-azure-app-service-app-settings-in-arm-template/
Please let me know if you have already implemented this or it helps in this case.