Yii2 authenticate through LDAP

Question

I installed "\stmswitcher\Yii2LdapAuth\LdapAuth" this package in yii2 for authenticate user through ldap. below is the configuration for ldap.

'ldapAuth' => [
    'class' => '\stmswitcher\Yii2LdapAuth\LdapAuth',
    'host' => 'ldap.forumsys.com',
    'baseDn' => 'dc=example,dc=com',
    'searchUserName' => 'riemann',
    'searchUserPassword' => 'password',

   // optional parameters and their default values
    'ldapVersion' => 3,             // LDAP version
    'protocol' => 'ldap://',       // Protocol to use
    'followReferrals' => false,     // If connector should follow referrals
    'port' => 389,                  // Port to connect to
    'loginAttribute' => 'uid',      // Identifying user attribute to look up for
    'ldapObjectClass' => 'person',  // Class of user objects to look up for
    'timeout' => 10,                // Operation timeout, seconds
    'connectTimeout' => 5,          // Connect timeout, seconds ]

Using above configuration I am able to connect to ldap server but not able to ldap bind I am facing below error.

So what I have done wrong? can any one help me?