https://www.apple.com/ca/shop/product/MD821AM/A/lightning-to-usb-camera-adapterhttps://www.apple.com/ca/shop/product/MK0W2AM/A/lightning-to-usb-3-camera-adapterI've personally used the first item (USB 2 version) with a keyboard just to give it a try. I would recommend the USB 3 version because it supports pass-through Lightning power. The USB 2 version has a very low power limit. The intended use case is to transfer photos from a self-powered digital camera via USB. I got it to work with one particular USB keyboard and one particular card reader, but my other devices draw too much power. You can connect it to a USB hub and try other USB peripherals. I tried a USB hub on my monitor and a USB Ethernet adapter and it works.
I just tried keyboard and mouse operation again. On iOS 12.x (the final version for iPhone 6) the mouse did
not work. The keyboard does work properly. On iOS 15.x, the mouse works as well. I think I had to toggle
Accessibility/Touch/Assistive Touch on to make it work the first time. Afterwards, the mouse still works with
Assistive Touch off. I can unplug and plug it again and the mouse still works.
However, there is a security setting under
Touch ID & Passcode/USB Accessories. If
USB Accessories is turned off, you can't connect any USB device while the phone is locked. This would prevent you from entering the passcode with a keyboard or mouse. I'm not sure of the default setting for
USB Accessories.
To the original poster, charge up the phone, press the lock button and try the touchscreen. If you hear the clicks from the speaker from touching the touchscreen, you have a chance of recovering your photos. Try entering the passcode on the blank screen. If you have another iPhone of the same size, you can use it as a guide for where to tap on the screen.
If you get it unlocked, you can try connecting the Lightning to USB cable to your computer. You will get the
Trust This Computer popup. If you can manage to the hit the
Trust button, you will be connected via USB PTP and should be able to copy the photos off.