I believe iOS and iPadOS both support standard HID devices if connected through a USB-to-Lightning or USB-C adapter. I've used a Logitech MX Ergo on an iPad Min

I believe iOS and iPadOS both support standard HID devices if connected through a USB-to-Lightning or USB-C adapter. I've used a Logitech MX Ergo on an iPad Mini and thought that was pretty neat. I thought about getting a Magic keyboard and pairing that and the Ergo to the iPad as a lightweight SSH solution for traveling.