[API] Getting the list of pending and running builds

I am trying to use the REST API /api/v3/projects/:id/builds/ to get the list of all builds. It works, but in the documentation, it says that I could add a scope to show, one or array of: pending, running, failed, success, canceled; showing all builds if none provided.

I could make work a single item (/api/v3/projects/:id/builds/?scope=success), but it is always failing with an array.

What is the correct syntax for all ‘pending’, ‘running’ builds for instance?