Why is the fiber inspection probe for the AQ6380 not connecting?

The AQ6380 fiber inspection probe needs to be plugged into the bottom USB port.

AQ6380 OSA: 5 pm (0.624 GHz) high wavelength resolution, ±5 pm accuracy, 65 dB wide close-in dynamic range, 80 dB high stray light suppression

Optical Spectrum Analyzer is used to measure and display power distribution of an optical source
Optical analyzer traces and displays power in vertical scale and wavelength in horizontal scale