Neither Competex Pro nor any other payroll umbrella company ever provides work-finding services of any kind. This is the role of the interim providers and agencies. Although you become an employee of Competex Pro, you will be paid only when you are on assignment. In return, and unusually in an employer-employee relationship, all the funds that you earn, less a small administrative margin, are ring fenced and used to pay you salary, and expenses.
You have no obligations to the company between assignments and it follows that you are not obliged to keep yourself available for work between assignments.
The onus, therefore, is on you to find your own work, and Competex Pro will of course normally be very happy to provide the framework within which you can operate. However, please be aware that we are under no obligation to accept work for you, and to arrange for you to work through us, if the nature of an assignment is not acceptable to us.