LDAP Auth doesn't work

I had setup the vault in the cluster, and I could login through my root token. Now I’m trying to setup LDAP authentication. I had followed the below document exactly but had this error.

Document: LDAP - Auth Methods | Vault | HashiCorp Developer
Error authenticating: Error making API request.
Code: 400. Errors:

  • ldap operation failed: failed to bind as user