I'll take a stab.
if you execute that command, you'll see it is using the IPBX repo. From there, it explains how to change it to FPBX if you so desire.
From the other binaries in the directory, you can use them to install any Module that you so desire. I decided to install the Fax module from the fpbx repo using the list and install commands.
As for the error itself, maybe there is no ipbx16 repo yet? That is a total guess, not sure the answer to the actual error.