Ethernet connection not available in network list on iMac 2017
I need to connect a router by ethernet to configure it. However ethernet connection does not appear in the list in network connection setting on my iMac 2017. It wasn't there before I just upgraded to Big Sur and it's still not there.
Please could someone advise how I can either set it up again or download a fix so I can use ethernet connection again, also for internet access via ethernet in the future if I need to.
Thanks in advance,
Cora
iMac 27″ 5K, macOS 11.2