Again, you’re following the wrong flow…
https://knowledge.kaltura.com/obs-studio-and-kaltura-live-streaming is only relevant if you’re working against our SaaS ENV [i.e www.kaltura.com]. It will NOT work with self hosted CE ENVs.
You need to follow https://blog.kaltura.com/free-and-open-live-video-streaming, instead.
See also: Live streaming working great