Below i am posting the example of  ODOO Api access from php using ripcord library :

require_once('ripcord-master/ripcord.php');

$url = "http://localhost:8059";           //ODOO  Server Url
$db ="ripcord_test_db";                   //Database Name
$username = "prakasharmacs24@gmail.com";  //UserName 
$password = "7959884833";                 //Password
$common = ripcord::client("$url/xmlrpc/2/common");

//Authenticate the credentials
$uid = $common->authenticate($db, $username, $password, array());
echo $uid;  //1

//Create Model Instance 
$models = ripcord::client("$url/xmlrpc/2/object");

// Fetch the data by calling appropriate methods
$partner_field = array();
$partner_field=$models->execute_kw($db, $uid, $password,
                           'res.partner', 'fields_get',array(),
                            array('attributes' => array('string', 'help', 'type')));

Hope this may code may be help full for reference 

The documentation provides snippets in PHP (among other languages). See the XML-RPC API section here: https://www.odoo.com/documentation/9.0/api_integration.html