private static function makeRequest($key, $secret, $account)
    {
        $credentials = base64_encode($key . ':' . $secret);
        $endpoint = Core::instance()->getEndpoint(MPESA_AUTH, $account);

        return Core::instance()->client()->request('GET', $endpoint, [
            'headers' => [
                'Authorization' => 'Basic ' . $credentials,
                'Content-Type'  => 'application/json',
            ],
        ]);
    }
private static function makeRequest($key, $secret, $account)
    {
        $credentials = base64_encode($key . ':' . $secret);
        $endpoint = Core::instance()->getEndpoint(MPESA_AUTH, $account);

        return Core::instance()->client()->request('GET', $endpoint, [
            'headers' => [
                'Authorization' => 'Basic ' . $credentials,
                'Content-Type'  => 'application/json',
            ],
        ]);
    }
private static function makeRequest ( $ key , $ secret , $ account ) { $ credentials = base64_encode ( $ key . ':' . $ secret ) ; $ endpoint = Core :: instance ( ) -> getEndpoint ( MPESA_AUTH , $ account ) ; return Core :: instance ( ) -> client ( ) -> request ( 'GET' , $ endpoint , [ 'headers' => [ 'Authorization' => 'Basic ' . $ credentials , 'Content-Type' => 'application/json' , ] , ] ) ; }
Initiate the authentication request.

@return mixed|\Psr\Http\Message\ResponseInterface
Initiate the authentication request .