Use of OTG with iPhone 13

Based on the iPhone models get one of the following accessories from an Apple Store.

• Lightning to SD Card Camera Reader
• USB-C to SD Card Reader

Connect a USB drive or an SD card reader. Attach the USB drive or SD card reader to the charging port on your iPhone using a compatible connector or adapter.

Connect external storage devices to iPhone

If it has a lightning connector you can use it, but i would not connect just anything to your iPhone, but that is maybe my paranoia with things ike that

I would absolutely NOT connect something like that to my phone.