Hope you have enabled SSL/HTTPS for your ALM URL. This means your keystore.jks file must be in <ALM deployment path>/server/conf. The default password of keystore file is "changeit" but any password can be setup while creating .jks file.
Now, in order to enable LDAPS you may look https://admhelp.microfocus.com/alm/en/16.00-16.0.1/online_help/Content/sa_users_import_LDAP_SSL.htm
To enable SSL/HTTPS look at Installation & Upgrade doc page # 137-139 admhelp.microfocus.com/.../Install_Linux.pdf