With built-in USB PORT outside, this laptop backpack is convenient to charge your cell phone by the connected power bank. USB PORT INSTRUCTIONS:Putting your Power Bank (NOT INCLUDED) into backpack and connect internal USB cable, then let your charging cable insert external USB port to connect your electronic device.
https://www.amazon.com/KROSER-Backpack-Computer-Water-Repellent-Women-Black/dp/B07MK6J5NT