Connect 2022 Mac mini to iMac to use it as a display
I have a brand new Mac mini m1. I have 2 iMac 27”, 2013 and 2015. My understanding is I can’t do this with the 2015 iMac. Mini came with a thunderbolt cable. But it looks like the iMac thunderbolts are incompatible. Can you suggest the easiest and cheapest way to connect this new thunderbolt cable on iMac, assuming there is an adapter. If not, please suggest other cables. A link to the cable would be appreciated so I get the right one. TIA!
[Re-Titled by Moderator]