Trouble finding drop-down for adding spaces in Sanity.io

Hi,I am trying to add spaces to allow for toggling between datasets c.f.
https://www.sanity.io/docs/spaces I am not able to find the drop-down anywhere in the UI though - does anybody know where am I supposed to find it?

Ah i figured it out - I though I had to remove the "api" property because it would be replaced by the __experimental_spaces, but that's not the case