require - How to setup Guzzle 3 for sendgrid php without composer -

in php webapplication migrate mandrill sendgrid transaction emails.

i added sendgrid php folder application so:

require_once docroot . 'vendor' . directory_separator . 'sendgrid-php' . directory_separator  . 'sendgrid-php.php'; 

but when know try use sendgrid, error, need guzzle:

class 'guzzle\http\client' not found 

so need add guzzle 3 (because sendgrid still relying on guzzle 3) webapp. guzzle 3 not have simple file autoloads other files, how integrate webapp?

now im using "guzzlehttp/guzzle": "^6.2" , , it's worked when

use guzzle\http\client