@Sebastien If you use the gripper and the camera together, you will not need the USB converter. When you mount the gripper and the camera on a UR robot, the gripper's power and communication are provided via the camera's spring pin connector. This connection helps avoid a second cable running along the robot, since the single USB cable will provide communication for both the gripper and the camera. The 24V and ground wires will also power both products.
The following thread illustrates this shared connection between a 2F85 gripper and the wrist camera.
I would like to know if I need the USB converter if I use the gripper with the camera?