Openldap add user to secondary group

Linux and Unix-Like Linux
1

Hello,

i try to add user john to secondary group, named groupB

this will add as primary group,
how can i add to secondary group??

dn: cn=groupB,ou=Groups,dc=ldap-server,dc=com
changetype: modify
add: memberuid
memberuid: john
2

memberUid (because it's defined in the posixGroup object class) would be used for the secondary group. gidNumber (in the user's entry (uid=john,ou=Accounts,...)) would define the primary group for "john"