Hello @Andrew Hawken Apologies for late response here! After discussion with PG the update is:
"Not at this point – no – given 4.8.1 requires WS2022 for server OS’. And there is no ETA at this time to communicate on when the underlying platform will move to WS2022."
One possibility is to use Windows Containers. Here you can follow the quickstart to run a Windows Container in App Service:
Quickstart: Run a custom container on App Service - Azure App Service | Microsoft Learn
For your app, recommended to use the following image as base:
For more information: https://mcr.microsoft.com/en-us/product/dotnet/framework/aspnet/about