Hi, I am using FunctionApp (classic) to create function apps but it does not support beyond .NET 6. error: azureappservice/functionAppFunctionApp resource 'test-v8-function-app' has a problem: expected site_config.0.dotnet_framework_version to be one of ["v4.0" "v5.0" "v6.0"], got v8.0. Examine values at 'test-v8-function-app.siteConfig.dotnetFrameworkVersion'. I tried to create .NET 8 based WindowsFunctionApp (classic) but getting following error * A resource with the ID "/subscriptions/......./resourceGroups/......./providers/Microsoft.Web/sites/test-v8-function-app" already exists - to be managed via Terraform this resource needs to be imported into the State. Please see the resource documentation for "azurerm_windows_function_app" for more information.: A resource with the ID "/subscriptions/......./resourceGroups/....../providers/Microsoft.Web/sites/test-v8-function-app" already exists - to be managed via Terraform this resource needs to be imported into the State. Please see the resource documentation for "azurerm_windows_function_app" for more information. I want to upgrade my existing function apps created with FunctionApp (classic) to .NET 8.

Function Apps only support .Net 6, if you want to use anything later you need to migrate to the isolated worker model. They've talked about supporting .Net 8, however they're deprecating the in-process worker model in 2026 so it's worth looking into switching to isolated worker anyway.