Calling 3rd party shipping provider plugins

If you're trying to use a 3rd party shipping plugin by putting the plugin's System Name in the Option rule's Rate Expression but get an error e.g., "Error=No property or field 'ThirdParty' exists in type 'QueryContext'", then you need to prefix the name with "Shipping".

For example if your Rate Expression has

     ThirdParty.UPS

Then change it to read

     Shipping.ThirdParty.UPS