LDAP server &1 provides no transport layer security for user passwords

What causes this issue?

The function of "Delayed Authentication" sends the users password to a
directory service.
In order to protect the password on the transport layer, this
functionality requires that transport layer security is enabled for the
directory service. The currently chosen directory service from ABAP
customizing (transaction LDAP, function "LDAP Servers") does not fulfil
this requirement.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Procedure for System Administrators

"Delayed Authentication" requires that the ICM LDAP plug-in is used (the
LDAP Connector is not supported)<(>,<)> and the security protocol is set
to either STARTTLS or LDAPS.

Error message extract from SAP system. Copyright SAP SE.