Can't boot into recovery mode on new iMac, Big Sur OS.
I tried to boot into recovery mode using command-R and the computer booted as usual. A previous similar question had successfully booted into recovery by unplugging an external hard drive. So I tried that, also unsuccessful. So I unplugged everything except my internet connection. Still unsuccessful. So is it impossible to boot into recovery mode on the new iMac, or is there something else to try?
iMac 24″, macOS 11.5