Converting and old 4.7 app to .net6 and unsure how to change old calls to methods which are not in 6

I am converting an old app to .net6 but cannot find a solution for a couple of errors which I am getting.

Any help would be appreciated

        public static DbConnection Connection(HttpContextBase httpContext, string configurationFileName, string connectionName)
        {
            Sources.ImportXmlStore(httpContext.Server.MapPath(configurationFileName));
            return Connection(connectionName);
        }

 error occuring on HttpContextBase

            internal static Configuration Find(string name)
            {
                // Search configurations used and imported from xml stores.
                Configuration configuration = _configurations.Value.Find(c => c.Name == name);
                if (configuration != null) return configuration;
                // TODO: Search configurations in settings.setting.

                // Search configurations in web.config and <applicationname>.config.
                var newconfiguration = new Configuration()
                {
                    Name = name,
                    ConnectionString = WebConfigurationManager.ConnectionStrings[name].ConnectionString,
                    ProviderName = WebConfigurationManager.ConnectionStrings[name].ProviderName,
                    Provider = AddProvider(WebConfigurationManager.ConnectionStrings[name].ProviderName)
                };
                _configurations.Value.Add(newconfiguration);
                return newconfiguration;

            }

Error occuring on ConnectionString[name]

References are

using System;
using System.Collections.Generic;
using System.Data.Common;
using System.Linq;
using System.Xml.Linq;
using System.Security.Cryptography;
using System.Web;                       // requires a reference to System.Web.dll
using Microsoft.Web.Administration;