Sdl.Web.Tridion.TopologyManager.GetSearchQueryUrl C# (CSharp) Method

        internal static string GetSearchQueryUrl(Publication publication, string environmentPurpose)
        {
            string publicationId = publication.Id.ToString();
            MappingData mapping = TopologyManagerClient.Mappings.Expand("CdEnvironment")
                .Where(m => m.PublicationId == publicationId && m.EnvironmentPurpose == environmentPurpose).FirstOrDefault();
            if (mapping == null || mapping.CdEnvironment == null)
            {
                return null;
            }

            string dxaSearchQueryUrl =  mapping.CdEnvironment.ExtensionProperties
                .Where(ep => ep.Name == "DXA.Search.QueryURL")
                .Select(ep => ep.Value)
                .FirstOrDefault();

            return dxaSearchQueryUrl;
        }