Power cable for new iMac 24” 2021

Contact Apple Support again and tell them you need a replacement power cabler (one that plugs into the back of your iMac and unto a power plug) for your 24" iMac, either with the Ethernet option or without - you choose.

Another option would be to visit the nearest Apple Genius Bar or Apple Authorized Service Provider and tell a(nd show) them what you need.

There are two different power cables for the M1 iMac. One with an Ethernet port, one without. You need to contact Apple Support to see about a replacement.

FWIW, we're all just fellow users here. I have no idea if there is a third-party supplier. I think you still need to deal with Apple support.