clarification on hub native domain

docs/setup-custom-domain.md

@@ -38,7 +38,7 @@ The easiest method to connect a custom domain to your Hub is to create a [cname]
 
 ## Part C: Connect Your Custom Domain
 
-1. Open a command terminal on your device and run the following command with the 3 parameters surrounded by `< >` replaced with your specific information from previous steps:\
+1. Open a command terminal on your device and run the following command with the 3 parameters surrounded by `< >` replaced with your specific information from previous steps. Your Hub's native domain is the URL assigned upon creation (ex: 123456.us1.myhubs.net)\
    `curl -X PATCH -H "turkeyauthtoken:<token-value-from-part-b>" 'https://<your-hubs-native-domain>/api/ita/custom-domain?to_domain=<desired-custom-domain>'`
 
 2. The command should execute quickly and return the following message:\