builder.Services.AddRazorPages(op =>

{

    op.Conventions.AddFolderRouteModelConvention("/", model =>

    {

        foreach(var selector in model.Selectors)

                {

            var c = selector.AttributeRouteModel.Template.ToString();

            selector.AttributeRouteModel = new AttributeRouteModel

            {

                Order = -1,

                Template = builder.Environment.EnvironmentName+"/"+c

            };

        }

    });

});

public class MyConstraint : IRouteConstraint

    {

        //add the enviroment here

        private static readonly string[] AllowedValues = new string[] { "Development", "Production" };

        public bool Match(

            HttpContext? httpContext, IRouter? route, string routeKey,

            RouteValueDictionary values, RouteDirection routeDirection)

        {

            if (!values.TryGetValue(routeKey, out var routeValue))

            {

                return false;

            }

            var routeValueString = Convert.ToString(routeValue, CultureInfo.InvariantCulture);

            if (routeValueString is null)

            {

                return false;

            }

            return AllowedValues.Contains(routeValueString, StringComparer.InvariantCultureIgnoreCase);

        }

    }

builder.Services.AddRouting(options =>

    options.ConstraintMap.Add("myconstraint", typeof(MyConstraint)));

// Add services to the container.

builder.Services.AddRazorPages(op =>

{

    op.Conventions.AddFolderRouteModelConvention("/", model =>

    {

        foreach(var selector in model.Selectors)

                {

            var c = selector.AttributeRouteModel.Template.ToString();

            selector.AttributeRouteModel = new AttributeRouteModel

            {

                Order = -1,

                Template = "{enviroment:myconstraint}/" + c

            };

        }

    });

});