Internet connectivity on iPhone 13 mini using ethernet cable or reverse tethering not working

I am trying to use my iPhone 13 mini apps and browser etc. by using my Sequoia iMac's internet connection or my broadband router.

I have a USB cable for the iPhone to connect it to the iMac (using a lightning adapter) - the iPhone appears in Finder. I have sync'd Calendar etc. using that cable. I read that you can use this cable to connect to the internet in flight mode but it requires reverse tethering to be enabled. Google AI says it's not possible and only tethering is possible (i.e. allowing the iMac to use the iPhone's 4G or other internet connection). Some threads seem to suggest it is possible but they are not clear. I enabled internet sharing on my iMac but when I do this the internet connection drops totally on the iMac, so I have to disable it and reboot the Mac to get the internet back.

I have a TP-Link Ethernet to USB adapter, which is tested working on the iMac but using it with the same lightning adapter on the iPhone, it is not detected. 'Ethernet' is supposed to appear in the settings screen under Wifi but it does not appear.

Any ideas please?