Why is the hostname not set/missing in the API Management Portal?

I checked the API settings and policies, but I cannot find anything regarding the hostname.
This API is configured with a selfhosted gateway.

CodePudding user response：

I found the reason. Usually, I configured the selfhost-gateway and the managed gateway:

If I remove the managed gateway, I have to specify the hostname in the Developer Portal with the hostname of the selfhosted-gateway.