After enrolling the Gateway with your Portal instance you may want to change the API Proxy URL as shown here.
You may have entered the wrong API Proxy URL upon the initial enrollment of the Gateway to the Portal instance or something may have changed in your environment where you would like to change this
Release : 4.x
Component : API PORTAL
In order to change this Proxy URL you must re-enroll the Gateway with the Portal instance.
Please be aware that the value shown in the API Proxy URL is cosmetic in nature and has no bearing or relevance on Gateway / Portal functionality. There is no need to change this other than a more consistent view from the Portal User Interface.
Enroll a Layer7 API Gateway