Hi @Amit Thore ,
One way to install custom fonts in Azure App Service is to use a custom Windows container. You can deploy a custom-configured Windows image from Visual Studio to Azure Container Registry, and then run it in App Service. This allows you to make OS changes that your app needs, such as installing custom fonts. Please follow this tutorial 'Migrate custom software to Azure App Service using a custom container" to achieve this. You can also check out some other alternative ways to achieve this shared on this related SO thread.
Hope that helps. Please let us know if you have further questions
Thanks,
Grace