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_00c71cb5-a3e7-4fb6-b5e4-06ac7bf7005a_yankable=1.0.0:cmp_ex"