How to print receipt to a USB printer on iOS?

[Andy]

Unfortunately, iOS devices do not support the USB by itself. So, there is no way to connect the USB printer to the iPad.

[Europelle SG]

I have a bluetooth printer that cannot be connected on iOS. I can only think of 2 solutions. First is to connect the printer directly to iPad via OTG cable. Second is to connect USB printer to AirPrint server and point iPad to it. Can anyone advise on this? I really need help on this!! :(

[Gabbi]

Hello! USB printers don't work with iOS devices, unfortunately.  You can use a printer from those recommended on website for iOS. If you want to use another printer then you should choose Ethernet interface.

[Blinken]

I found that there are a couple of USB printers officially supported on iOS!

Star TSP143IIIU (USB)
Star mC-Print3 (USB, Bluetooth, Ethernet)

How to Set Up a USB Printer with an iOS Device
https://help.loyverse.com/help/how-set-usb-printer-ios-device