No group membership attribute(s) found in user object

[Boudjoudad Abdelkader]

Hello,
Can someone help please !
I'm trying to update the post-auth using the condition in default file as
below:
if (&LDAP-Group == "groupname") {
Some processes
....
}
Or
if (&Group-Name== "groupname") {
Some processes
....
}

And in ldap file:
ldap {
...
base_dn = 'cn=users,cn=accounts,dc=example,dc=com'
...
}
...
group {
base_dn = "${..base_dn}"
filter = '(objectClass=posixGroup)'
name_attribute = cn
membership_filter =
"(|(member=%{control:Ldap-UserDn})(memberUid=%{%{Stripped-User-Name}:-%{User-Name}}))"
membership_attribute = memberOf
cacheable_name = 'yes'
cacheable_dn = 'yes'
# cache_attribute = 'LDAP-Cached-Membership'

But i'm getting:
No group membership attribute(s) found in user object

What i'm missing ?

Thanks,