Hello, yes, they show upgrade options, but good luck finding a part number!
I have found dell Very Difficult in many ways, their techs can’t even understand the hieroglyphics used in the product specs!

regards, Brent 

https://www.dell.com/support/kbdoc/en-us/000127539/upgrading-the-wd19-dock-with-the-cable-module-customer-kit