LDAP & Virtualmin & Debian 10

Hi,
I need a proper guide for setting LDAP on Debian with Virtualmin. I am willing to pay.

I know about this guide:
https://www.virtualmin.com/documentation/installation/ldap/

But there is a problem somewhere that postfix section is not working. No idea where is the problem so need a proper guide.

An example;
Guide says “Open the Manage Schema page, and make sure the nis schema is checked.”

But as u can see there is no checking in page:

Another problem for future readers;
LDAP Client module configuration looks for this file:
/etc/ldap.conf
which should be;
/etc/ldap/ldap.conf

Alias creation has problem…

Failed to save user : The additional email domain 'local.test' is not managed by Virtualmin

Paging @tpnsolutions