Here's an alternative for Laravel 7, or PHP only:

It does basically the same thing, but it works, although it's simple:

If you don't use laravel, adapting it is very easy, because laravel's http client uses Guzzle, the only thing you have to do is to replace the existing http client with the Guzzle client.

I hope it helps you...

https://github.com/juanal98/Laravel-Proxy-Helper