Mapping Area to Subdomain ASP.NET Core 7

I'm trying to Map areas I've created to subdomains and failing.

I have an area named "sugar" and I'm using a SubDomainRouteTransformer class I found online that worked for an ASP.NET core 5 project with the code:

    

    public class SubDomainRouteTransformer : DynamicRouteValueTransformer
    {
        public override async ValueTask<RouteValueDictionary> TransformAsync(HttpContext httpContext, RouteValueDictionary values)
        {
            var subDomain = httpContext.Request.Host.Host.Split(".").First();
            if (string.IsNullOrEmpty(subDomain))
            {
                values["controller"] = subDomain;
            }
            return values;
        }
    }

in my program.cs file I implement it thus

    builder.Services.TryAddTransient<SubDomainRouteTransformer>();

    app.MapControllerRoute(
        name: "default",
        pattern: "{controller=Home}/{action=Index}/{id?}");
    
    app.MapDynamicControllerRoute<SubDomainRouteTransformer>("Sugar", "{area:exists}/{controller=Home}/{action=Index}/{id?}");

However, whenever I try accessing the main website, which is the one under the "default" route, I keep getting directed to the "sugar" area. Is there a proper way I can implement this?

Firstly,with your codes,"Sugar" would be considered as the route parttern,you have to remove "Sugar"

Secondly

> whenever I try accessing the main website, which is the one under the
> "default" route, I keep getting directed to the "sugar" area

check if subdomain exists:

var host = httpContext.Request.Host.Host;
var subDomain = host.Split(".").Count() > 1 ? host.Split(".").First() : "";

If you don't want to be directed to Sugar area when subdomain doesn't exists,try

if (!string.IsNullOrEmpty(subDomain))
{
  values["controller"] = subDomain;
  values["area"] = subDomain;
}
else
{
   values.Remove("area");
 }

I tried with a minimal example:

in program.cs:

app.MapDynamicControllerRoute<SubDomainRouteTransformer>("{area}/{controller=Home}/{action=Index}/{id?}");

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Home}/{action=Index}/{id?}");

SubDomainRouteTransformer:

public class SubDomainRouteTransformer : DynamicRouteValueTransformer
    {
        public override async ValueTask<RouteValueDictionary> TransformAsync(HttpContext httpContext, RouteValueDictionary values)
        {
            var host = httpContext.Request.Host.Host;
            var subDomain = host.Split(".").Count() > 1 ? host.Split(".").First() : "";
            if (!string.IsNullOrEmpty(subDomain))
            {
                values["controller"] = subDomain;
                values["area"] = subDomain;
            }
            else
            {
                values.Remove("area");
            }
            return values;
        }
    }

Result: