You are using staging server - a separate instance of the ESP Component Registry that allows you to try distribution tools and processes without affecting the real registry.
To create a project from this example, run:
idf.py create-project-from-example "test_component_manager/test_a887f58d-a0a8-4763-a5d0-9f6693002d88_yankable=1.0.0:cmp_ex"