Azure Functions App Version Initializer

ApplicationVersionInitializer.cs

using System.Reflection;

using Microsoft.ApplicationInsights.Channel;
using Microsoft.ApplicationInsights.Extensibility;

namespace FunctionApp19
{
    public class ApplicationVersionInitializer<TStartup> : ITelemetryInitializer
    {
        public ApplicationVersionInitializer()
        {
            ApplicationVersion = typeof(TStartup).Assembly
                                                 .GetCustomAttribute<AssemblyInformationalVersionAttribute>()
                                                 ?.InformationalVersion;
        }

        public string ApplicationVersion { get; set; }

        public void Initialize(ITelemetry telemetry)
        {
            telemetry.Context.Component.Version = ApplicationVersion;
        }
    }
}

Startup.cs

using Microsoft.ApplicationInsights.Extensibility;
using Microsoft.Azure.Functions.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection;

[assembly: FunctionsStartup(typeof(FunctionApp19.Startup))]

namespace FunctionApp19
{
    public class Startup : FunctionsStartup
    {
        public override void Configure(IFunctionsHostBuilder builder)
        {
            builder.Services.AddSingleton<ITelemetryInitializer, ApplicationVersionInitializer<Startup>>();
        }
    }
}