Adding an http client to a .net project

1. Add the nuget package Microsoft.Extensions.Http
2. In your Startup.cs/Program.cs, add

using System.Net;
using Microsoft.Extensions.DependencyInjection;

// ... in ConfigureDomainServices, or where-have-you

string acvApiHost = configuration.GetSection("Services").GetSection("AcvApi")["Host"];
if (String.IsNullOrEmpty(acvApiHost))
    throw new ValidationException("Services__AcvApi__Host"); // Core.CustomExceptions
string acvApiToken = configuration.GetSection("Services").GetSection("AcvApi")["Token"];
if (String.IsNullOrEmpty(acvApiToken))
    throw new ValidationException("Services__AcvApi__Token");

services.AddHttpClient<AcvApiService>(c =>
    {
        c.BaseAddress = new Uri(acvApiHost);
        c.DefaultRequestVersion = HttpVersion.Version10; // it can't handle chunked
        c.DefaultRequestHeaders.TransferEncodingChunked = false;
        c.DefaultRequestHeaders.Add("Authorization", $"AcvAuth {acvApiToken}");
        c.DefaultRequestHeaders.Add("User-Agent", _userAgent);
    });