ldapadd -Y EXTERNAL -H ldapi:/// -f config-mydom-com.ldif

ldapadd: invalid option -- 'H'
usage: ldapadd [options]
... (list of options -H not included)

-H ldapuri
Specify URI(s) referring to the ldap server(s); only the protocol/host/port fields are allowed; a list of URI, separated by whetespace or commas is expected.