Custom api sugarcrm 8.0 not working

The function of my code is, i want it to capitalize the initial letters of the field firstname and last name when they click the Upper name button.

here's the code:

<?php

class UpperNameApi extends SugarApi
{
public function registerApiRest()
{
return array(
'UpperNameRequest' => array(
//request type
'reqType' => 'GET',

//endpoint path
'path' => array('Leads', 'UpperName'),

//endpoint variables
'pathVars' => array('module','record'),

//method to call
'method' => 'UpperNameMethod',

//short help string to be displayed in the help documentation
'shortHelp' => 'Example endpoint',

//long help to be displayed in the help documentation
'longHelp' => 'custom/clients/base/api/help/MyEndPoint_MyGetEndPoint_help.html',
),
);
}

/**
* Method to be used for my MyEndpoint/GetExample endpoint
*/
public function UpperNameMethod($api, $args)
{
if (isset($args['record']) && !empty($args['record'])) {
$bean = BeanFactory::getBean('Leads', $args['record']);

if (!empty($bean->id)) {
$first = $bean->first_name;
$first = ucwords($first);
$bean->first_name = $first;

$last = $bean->last_name;
$last = ucwords($last);
$bean->last_name = $last;
$bean->save();
}

return 'success';
}


return 'failed';

}

}

When i click the "Upper name button" it doesn't work:

i also tried using postman but this showed up: "error_message": "Could not find a route with 3 elements"

UPDATED

ive made another request in postman with this values but it shows: "A parameter in your request was invalid."

UPDATED AGAIN

PROBLEM FIXED.