AspNetBoilerplate - HttpContext is null in custom TenantResolveContributor - aspnetboilerplate

Question

Documentation
I've read the documentation at https://aspnetboilerplate.com/Pages/Documents/Multi-Tenancy
I added a custom TenantResolveContributor to the application project and added it to the collection in WebModule.PreInitialize.
Configuration.MultiTenancy.Resolvers.Add<NameTenantResolveContributor>();
In WebModule.Initialize, I resolve my TenantAppService so it can be injected into RouteConfig.
TenantAppService tenantAppService = IocManager.Resolve<TenantAppService>();
RouteConfig.RegisterRoutes(RouteTable.Routes, tenantAppService);
When execution reaches RouteConfig, it correctly goes into NameTenantResolveContributor, but the HttpContext is null.
I'm not sure what I need to do to fix this.
Abp package version : 6.0.0
Base framework: .Net
Request is not available in this context
at System.Web.HttpContext.get_Request()
at DemoApp.MultiTenancy.NameTenantResolveContributor.ResolveTenantId() in >D:\src\ABP\DemoProject\6.0.0\src\DemoProject.Application\MultiTenancy\NameTenantResolveContributor.cs:line 40
at Abp.MultiTenancy.TenantResolver.GetTenantIdFromContributors()
The stack trace is oddly brief and undescriptive. When I copy the details, the message is
System.Web.HttpException
HResult=0x80004005
Message=Request is not available in this context
Source=<Cannot evaluate the exception source>
StackTrace:
<Cannot evaluate the exception stack trace>
using Abp.Configuration.Startup;
using Abp.Dependency;
using Abp.Domain.Repositories;
using Abp.Extensions;
using Abp.MultiTenancy;
using Abp.Text;
using Abp.Web.MultiTenancy;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Web;
namespace DemoApp.MultiTenancy
{
public class NameTenantResolveContributor : ITenantResolveContributor, ITransientDependency
{
private readonly IMultiTenancyConfig _multiTenancyConfig;
private readonly ITenantStore _tenantStore;
public NameTenantResolveContributor(IMultiTenancyConfig multiTenancyConfig, ITenantStore tenantStore)
{
_multiTenancyConfig = multiTenancyConfig;
_tenantStore = tenantStore;
}
public int? ResolveTenantId()
{
string tenancyName = "";
string[] urlParts = null;
var httpContext = HttpContext.Current;
if (httpContext == null)
{
return null;
}
//This is where the error occurs
urlParts = httpContext.Request.Url.Segments.Select(x => x.TrimEnd('/')).Skip(1).ToArray();
tenancyName = urlParts[0].ToLower();
var tenantInfo = _tenantStore.Find(tenancyName);
if (tenantInfo == null)
{
return null;
}
return tenantInfo.Id;
}
}
}