Fix

src/Services/TenantCustomisations/TenantACustomisations/Database/DbInitializer.cs

@@ -23,7 +23,7 @@ namespace TenantACustomisations.Database
             shippingInformation.FragilityLevel = Fragility.Medium;
             shippingInformation.PriorityLevel = Priority.High;
             shippingInformation.ShippingInformationId = 1;
-            shippingInformation.OrderNumber = 1;
+            shippingInformation.OrderNumber = "1";
             context.ShippingInformation.Add(shippingInformation);
 
             context.SaveChanges();

src/Services/TenantCustomisations/TenantACustomisations/ExternalServices/MockedShippingService.cs

@@ -15,7 +15,7 @@ namespace TenantACustomisations.ExternalServices
             shippingInformation.ArrivalTime = DateTime.Today.AddDays(2);
             shippingInformation.FragilityLevel = Fragility.Medium;
             shippingInformation.PriorityLevel = Priority.High;
-            shippingInformation.OrderNumber = orderId;
+            shippingInformation.OrderNumber = orderId.ToString();
 
             return shippingInformation;
         }