When a client creates a job, it will appear on the Job petition and will not be confirmed/live until it's approved by the agency.
You can click on the Job petition (blue drawer next to Jobs) and either Accept or Reject it.
When you accept it, it will open the Create New Job wizard. You can follow the normal process from here. Information that the client has entered like the name of the job, schedule, and number of positions will be auto-populated. The rest is BAU (business as usual) for a job creation process. Make sure you note the Preferred Candidate listed by the client so that you allocate the candidate to the assignment if they are available.