It is one of these connectors: https://en.wikipedia.org/wiki/USB_hardware#USB_On-The-Go_connectors https://en.wikipedia.org/wiki/USB_hardware#USB_On-The-Go_con

It is one of these connectors: https://en.wikipedia.org/wiki/USB_hardware#USB_On-The-Go_connectors https://en.wikipedia.org/wiki/USB_hardware#USB_On-The-Go_con... But every OTG device I have ever used has just used the USB-A port.