• https://sterlingit.com.au/how-to-create-a-user-or-admin-user-in-osx-apple-mac-via-terminal-commands-in-9-simple-steps/

sudo -s
 
dscl . -create /Users/foo
dscl . -create /Users/foo UserShell /bin/bash
dscl . -create /Users/foo RealName "Foo Bar"
dscl . -create /Users/foo UniqueID 1008
dscl . -create /Users/foo PrimaryGroupID 1008
dscl . -create /Users/foo NFSHomeDirectory /Local/Users/foo
dscl . -passwd /Users/foo "SecretPassword2"
 
dscl . -append /Groups/admin GroupMembership foo