thank you Jess i used kaltura secret in developers->test console and it added the chapter.
from the chaptersEdit.qunit.html unfortunatelly i didnt manage to do that even with the kaltura secret
Was traying it as well locally but the same problem.
But since i know how to add it from test console or from my external written html page i dont need it to work, I can add the cuePoints from other place. This post can be closed or marked solved.