In BPM on Cloud you can invite user to sign up BPM environment via dashboard. When you invite user, user will be inactive till he/she signs up.
But If you want to create and activate a user without signing up (for SSO) you can call the rest api below.
But before call this api, you need ask IBM and to set “activate_automatically” option to true. If you don’t do that, you will get an error.