LDAP Authentication Proxmox VE

Datacenter -> Permission -> Authentication -> Add -> LDAP Server

Realm:  <your ldap name>
Base Domain Name: ou=Users,dc=example,dc=com
User Attribute Name: cn
Default: unchecked/No
Server: <ldap server ip>
Fallback Server: <ldap slave serverip if you have one>
Port: 389
SSL: unchecked/No
TFA: None
Comment: LDAP authenication server

Datacenter -> Permission -> Users-> Add

Username: <cn of a ldap user like test.user>
Realm: LDAP authenication server
Group: admin (you need to previously create one first and assign Roles to Group via CLI)
Expire: Never
Enabled: checked/Yes
First Name: <ldap givenName>
Last Name: <ldap sn>
Email: <ldap mail>
Comment: <blank>
Keys IDs: <blank>

Please note that PVE does not automatically populate user/group information like other packages.  It uses ldap server primarily only for password authentication only. Also, LDAP Realm Users cannot access server console via web interface