How can I configure an Azure Function to work with dynamic configuration using Azure App Configuration?

I’m trying to write an Azure Function that works as a multi-tenant. When a clientId comes from the clients as a parameter, I need to fetch its configuration from Azure App Configuration using labels.

Let me explain in a pseudo code;

I’m using .Net 6 Azure Function Isolated.
I made configuration in Program.cs like in the below code;

new HostBuilder()
.ConfigureAppConfiguration(builder =>
{
    string cs = "connection-string"; //which is actually comes from environment veriable
    builder.AddAzureAppConfiguration(options =>
    {
        options.Connect(cs);
        //options.Select(KeyFilter.Any, Environment.GetEnvironmentVariable("ClientId")); //It works that way, but I don't want to do it. I need to read the clientId while I receive the request
    });
})

Let’s assume that we made a middleware and a request came out

public RequestMiddleware(){
   //Here I need to inject some service
}

//Invoke method of middleware
public async Task Invoke(FunctionContext context, FunctionExecutionDelegate next){
  HttpRequestData requestData = await context.GetHttpRequestDataAsync();
  requestData.Headers.TryGetValues("client-id", out var clientId);
  var id = clientId.First();
  //And here, I need to configure App Configuration to use the id as a label. As I did in the Program.cs
 //like this ; options.Select(KeyFilter.Any, id);
}

Does it possible to load configuration by the label in the request lifecycle? Please keep in mind that Azure App Configuration in the standard tier has a limitation on requests, 3000 per hour. That’s why it won’t be a good idea to load AppConfiguration each time.