How to create catch-all email alias for domain in iRedMail Open Source edition?

I know that's possible via LDAP and found the following instructions: http://iredmail.org/wiki/index.php?title=Addition/OpenLDAP/Catch-all

The problem is how exactly to add this parameters via phpLDAPAdmin?

I select "Create new entry here" and choose mailUser type.

Then in step 2 first question is about "RDN" with select box "select RDN attribute".

What should I choose as RDN? Which fields of the "Create Object" form should be filled?

Unfortunetly there is completely no validation of user input and final errors does not contain explanation what's wrong

Also when I try to import example from iredmail wiki phpldapadmin it gives LDIF Import Parse Error Description: A valid dn line is required []

dn line is: dn: [email protected],ou=Users,domainName=mydomain.eu,o=domains,dc=myserver,dc=pl