Help my - problem on slapd service

[Сидоренко Сергей Васильевич]

Good afternoon!
I ask for help in configuring the slapd service installed on the ubuntu 
20.04 server with the latest updates.

  We use this server as the LDAP global address book for the mail 
server. When the service is started, errors are reflected in its status. 
The slapd service starts and works, but I would like to fix the settings.
Can you tell me how to fix the errors, where to see the documentation on 
these errors?
An Internet search did not bring results, you are the last hope. Below 
is the service status:


localadm at mx:/etc/ldap$ sudo service slapd status
● slapd.service - LSB: OpenLDAP standalone server (Lightweight Directory 
Access Protocol)
      Loaded: loaded (/etc/init.d/slapd; generated)
     Drop-In: /usr/lib/systemd/system/slapd.service.d
              └─slapd-remain-after-exit.conf
      Active: active (running) since Fri 2023-03-10 11:34:42 MSK; 1s ago
        Docs: man:systemd-sysv-generator(8)
     Process: 623713 ExecStart=/etc/init.d/slapd start (code=exited, 
status=0/SUCCESS)
       Tasks: 3 (limit: 7009)
      Memory: 5.0M
      CGroup: /system.slice/slapd.service
              └─623742 /usr/sbin/slapd -h ldap:/// ldapi:/// ldaps:/// 
-g openldap -u openldap -F /etc/ldap/slapd.d

Mar 10 11:34:42 mx.mc-vesta.com systemd[1]: Starting LSB: OpenLDAP 
standalone server (Lightweight Directory Access Protocol)...
Mar 10 11:34:42 mx.mc-vesta.com slapd[623713]:  * Starting OpenLDAP slapd
Mar 10 11:34:42 mx.mc-vesta.com slapd[623734]: @(#) $OpenLDAP: slapd  
(Ubuntu) (May 12 2022 13:11:05) $
                                                        Debian OpenLDAP 
Maintainers <pkg-openldap-devel at lists.alioth.debian.org>
Mar 10 11:34:42 mx.mc-vesta.com slapd[623734]: sql_select option missing
Mar 10 11:34:42 mx.mc-vesta.com slapd[623734]: auxpropfunc error no 
mechanism available
Mar 10 11:34:42 mx.mc-vesta.com slapd[623734]: _sasl_plugin_load failed 
on sasl_auxprop_plug_init
Mar 10 11:34:42 mx.mc-vesta.com slapd[623742]: slapd starting
Mar 10 11:34:42 mx.mc-vesta.com slapd[623713]:    ...done.
Mar 10 11:34:42 mx.mc-vesta.com systemd[1]: Started LSB: OpenLDAP 
standalone server (Lightweight Directory Access Protocol).