my imac running 10.11.6, doesn't recognize my iphone 12 pro when i plug it in

Hello,I'm having an ongoing problem. My imac, running os 10.11.6, doesn't recognize my iphone 12 pro when i plug it in. In itunes, it doesn't show the icon when an iphone is connected. I purchased the used iphone with the idea that i was upgrading my phone/computer setup, but i didn't expect this. My iphone 8 plus doesn't do this, so it don't think it's the connector cable. Can anyone help me?