$ createuser -P -d -s -e my_user2 --host myhost.com -U my_user1
Enter password for new role: XXXYYYZZZ
Enter it again: XXXYYYZZZ
Password: password1
CREATE ROLE my_user2 PASSWORD 'md5999999c0101a1d64afd57575e06f999c' SUPERUSER CREATEDB  CREATEROLE INHERIT LOGIN;
createuser: creation of new role failed: ERROR:  must be superuser to create superusers
$

$ createuser -P -d -e my_user2 --host myhost.com  -U my_user1
Enter password for new role:
Enter it again:
Password:
CREATE ROLE my_user2 PASSWORD 'md5999999c0101a1d64afd57575e06f888c' NOSUPERUSER CREATEDB NOCREATEROLE INHERIT LOGIN;
$

dg+