Can I add external storage
You could with a flash drive that has a lightening connector.
While Apple devices like the iPhone do not have a slot for a memory card you can get a compatible USB drive to connect to it, you can get more details at the manufacturer's site:https://support.apple.com/guide/iphone/connect-external-devices-or-servers-iph8d8f0f1a0/ios
What is the reason you are looking to add storage to your device?
