[Samba] Problem adding sshPublicKeys to schema.

[Reese Wang]

Hi,
I'm following Samba AD schema extensions wiki page to add
sshPublicKeys to schema, but ldbmodify returned the following error:

# LDB_MODULES_PATH=/usr/lib64/samba/ldb/ ldbmodify -H
/var/lib/samba/private/sam.ldb Sshpubkey.ldif.txt
--option="dsdb:schema update allowed"=true
ERR: (Constraint violation) "000020B5: Referenced object not found at
../../source4/dsdb/samdb/ldb_modules/extended_dn_store.c:357:extended_replace_callback"
on DN CN=sshPublicKey,DC=ad,DC=example,DC=org at block before line 16
Modify failed after processing 0 records

What am I missing here? I'm using Samba 4.18.6 in Arch Linux docker container.
My Sshpubkey.ldif.txt:
dn: CN=sshPublicKey,DC=ad,DC=example,DC=org
changetype: add
objectClass: top
objectClass: attributeSchema
attributeID: 1.3.6.1.4.1.24552.500.1.1.1.13
cn: sshPublicKey
name: sshPublicKey
lDAPDisplayName: sshPublicKey
description: MANDATORY: OpenSSH Public key
attributeSyntax: 2.5.5.10
oMSyntax: 4
isSingleValued: FALSE
objectCategory: CN=Attribute-Schema,DC=ad,DC=example,DC=org
searchFlags: 8
schemaIDGUID:: cjDAZyEXzU+/akI0EGDW+g==