How to switch over from LDAP to LDAPS?


Recently our organization decided to switch LDAP connection to LDAPS, i imported the certificate by this command but still, I’m unable to make successful LDAP connection
Command used to import cert:-
keytool -importcert -alias lkdc01 -keystore /usr/lib/jvm/java-8-openjdk-amd64/jre/lib/security/cacerts -file my-ca.der

when i try to import certificate via icinga x509 module i get this-
icingacli x509 import --file /home/amasa/my-ca.der
Processed 0 X.509 certificates.

I’m not sure if i m on right path.
I’m able to have successful LDAP connection but always fails when I try the same with encryption- LDAPS on port 636.