LDAP Configuration for SSO Over the internet

Dear Team,

I am using active directory windows 2016 server and other applications both are different internet connectivity and location. 

My query is :- How to LDAP configuration with application over the internet for SSO (Without publish Active Directory Server).

1. Active directory windows 2016 server on ABC cloud's in vm.

2. Application server is also another XYZ cloud's in vm.