In case ldap_install_tls fails, should we call ldap_unbind_ext?

Hello, I have a question regarding libldap function ldap_install_tls().

If it fails, is it the right thing to call ldap_unbind_ext() after that?

If we call it, does it mean that ldap_install_tls() made a bind? Or do we call ldap_install_tls() on the connection that is already bound?

Sorry if the information is available somewhere, but I missed to find it. The only thing I found is that OpenLDAP server calls ldap_unbind_ext() in case of failure but maybe I miss something... https://git.openldap.org/openldap/openldap/-/blob/master/servers/slapd/back-...

Thank you, Simon