DropBox configration via composer - php

Question

Hello guys I'm new to composer thing. Previously I had configured dropbox manually in my codeigniter project but my head asked me to do it using composer now. I have configured composer somehow and installed dropbox using composer. Now this was my login function which I used before
public function login() {
// $this->CI->session->set_userdata('state', 1);
$this->CI->session->dropbox_success = false;
$oauth = new Dropbox_OAuth_PHP($this->CI->config->item('APP_KEY'), $this->CI->config->item('APP_SECRET'));
$this->dropbox = new Dropbox_API($oauth);
if ($this->CI->session->state) {
$state = $this->CI->session->state;
} else {
$this->CI->session->set_userdata('state', 1);
$state = 1;
}
switch ($state) {
/* In this phase we grab the initial request tokens
and redirect the user to the 'authorize' page hosted
on dropbox */
case 1 :
// echo "Step 1: Acquire request tokens\n";
$tokens = $oauth->getRequestToken();
// echo "<a href='".$oauth->getAuthorizeUrl(site_url())."' >Authorize</a>";
// header('Location: '. $oauth->getAuthorizeUrl());
echo "<img width='30px' src='" . base_url() . "somePAth'> Connect Dropbox";
$this->CI->session->set_userdata('state', 2);
$this->CI->session->set_userdata('oauth_tokens', $tokens);
return FALSE;
/* In this phase, the user just came back from authorizing
and we're going to fetch the real access tokens */
case 2 :
if (!$this->CI->session->oauth_tokens) {
$this->CI->session->set_userdata('state', 1);
header("Location: ?");
}
$oauth->setToken($this->CI->session->oauth_tokens);
$tokens = null;
try {
$tokens = $oauth->getAccessToken();
} catch (Exception $e) {
$this->CI->session->set_userdata('state', 1);
header("Location: ?");
return false;
}
$this->CI->session->set_userdata('state', 3);
$this->CI->session->set_userdata('oauth_tokens', $tokens);
header("Location: ?");
case 3 :
// echo "The user is authenticated\n";
$this->CI->session->dropbox_success = true;
$oauth->setToken($this->CI->session->oauth_tokens);
echo "<a class='btn btn-primary float-right' href=" . base_url('somePath') . ">Disconnect Dropbox</a>";
return true;
}
}
Now after I installed dropbox using composer and after going through the configration I created the app-info.json file and included the code which dropbox asked me to add in the code which is $oauth = dbx\AppInfo::loadFromJsonFile("../config/app-info.json"); in place of the second uncommented line but it's not working. It is throwing me this error.
ERROR : Exception of type 'Error' occurred with Message: Class 'dbx\AppInfo' not found in File D:\Ampps\www\softcake\application\libraries\Dropbox.php at Line 30
So can somebody please guide me what is it that I'm doing wrong and redirect me to some solution which would help me in configuring drop box in my app. Thanks in advance