API eventCategory segment not working

Hello,

I’m new to matomo and currently trialing the cloud version.
Using the API and can’t seem to get the eventCategory segment to work.

Here’s my request:

https://speckle.matomo.cloud/index.php?
idSite=2
&module=API
&period=range&date=2020-09-10,2020-09-22
&format=json
&method=Events.getCategory
&segment=eventCategory==stream
&token_auth=xxxxxx

I get this response:

{"result":"error","message":"The Segment you requested has not yet been created in the Segment Editor and so the report data has not been pre-processed. To see data for this segment, you must go to Matomo and create this segment manually in the Segment Editor. (Alternatively, you can create a new segment programatically using the SegmentEditor.add API method). Once created the segment in the editor (or via API), this error message will disappear and within a few hours you will see your segmented report data, after the segment data has been pre-processed. (If it does not, there may be a problem.) Please note that you can test whether your segment will work without having to wait for it to be processed by using the Live.getLastVisitsDetails API. When using this API method, you will see which users and actions were matched by your &segment= parameter. This can help you confirm your Segment matches the users and actions you expect it to."}

But the segment should be a default one AFAIK, this the events view form the UI:

I’ve also tried adding custom segments from the UI, but then I have no clue how to update my request…

Any help appreciated!
Thanks