Web API support for branches


I’m currently using a trial version of the develop plan with the branch plugin (1.0 (build 507).
My sonarqube version is Version 6.7.3 (build 38370)

I would like to try out getting branch information from the API (issues, settings etc). It should be available from the internal API as I understand a different post.

But I do not see it on my sonarqube server when I navigate to https://myinternal.srver.com/sonar/web_api/api/system ?
I do see it on a different SQ server on the internet (https://gazelle.ihe.net/sonar/web_api/)

What is going wrong with my server?
Somehow the next API call works: api/project_analyses/search?project=PC_civil-affairs&branch=F_sprint_5"
but it is not availabe in the webservice description (internal API) of my server

The problem is solved. It did not look correctly. How can I remove this post?