Have you tried clearing your cache? I'm about to go live and I can see the hosted streaming via zapstream's API just fine. I'm on Chrome (make sure you don't have ad-blocker or script blockers running).

If you can see that window grab the stream url and stream key and put them into the "streaming" setting in your OBS and when you go live your stream should appear on ZS. From there you can then optimise your OBS settings for your bandwidth, native resolution vs output, bitrate etc.

Also, feel free to jump into my streams any time to AMA zapstream.