How to run hp-levels on a cups shared printer?

I would like to show the ink level of a CUPS shared printer (network) from a computer of that network which the printer is not plug into like: computerA > server > CUPS > printerB : how to correctly run hp-levels from computerA to see the printerB ink level ? Is it possible?

Otherwise I tried to make a php script that run on the server but I can't get it to print something correct (my php script is like <?php passthru("hp-levels -i 2>&1"); ?>). It says Failed to create /var/www/.hplip and Unable to communicate with device (code=12): hp:/usb/Deskjet_5700?serial=MY4911Z0X7046W.

Thanks