Welcome to the HP Forums, this is a great location to get assistance! I read your post and see that you are unable to print photos on HP Sprocket. I would like to help you resolve this issue.
However, I will need a few details to provide an accurate solution,
When did this issue start?
Did you do any hardware or software changes?
To which device this printer is connected?
If you are unable to print with the HP sprocket app, use these recommendations to troubleshoot printing issues.
Turn on the printer: By default, the printer is set to turn off after 5 minutes. To change when the printer automatically turns off, open the HP sprocket app on your mobile device, and then tap the Menu icon . Tap sprocket, and then tap Printers. Select your printer in the list, tap Auto Off under the Settings section, and then select when you want the printer to turn off.
Charge the printer: On your mobile device, open the HP sprocket app, tap the Menu icon . Tap sprocket, and then tap Printers. Select your printer in the list, and then locate Battery under the Status section. If the battery is low, charge the printer by connecting it to a power source with the USB cable.
Make sure the printer has photo paper in the input tray: Load up to 10 sheets of HP Sprocket Photo Paper into the input tray with the HP logos facing down.
Confirm Bluetooth is turned on and paired with your printer: On your mobile device, make sure Bluetooth is turned on and paired with your printer.
If the printer is already paired to your mobile device, turning Bluetooth off and then on might resolve the issue.
Move the printer and your mobile device closer together: Bluetooth signals can be weaker at greater distances.
Upgrade the printer firmware: Open the HP sprocket app on your mobile device, and then look for a firmware upgrade in the sprocket menu.
Reset your mobile device: Turn off your mobile device, and then turn it back on to clear any error states.
Reset the printer. On the printer, locate the reset button underneath the paper cover, insert a straight pin into the reset button access point, and then press the reset button for 3 seconds. The printer resets and turns off.
Figure : Locating the reset button
Click here and refer this HP Document for more assistance.