Level 51
If you need your requests to come from an https url, you could always do valet secure in the root directory of your project. This means that Valet will serve your app via https. You might have to update your APP_URL in your .env file as well.
As far as Guzzle, this might help: https://stackoverflow.com/questions/33134274/how-do-we-specify-tls-ssl-options-in-guzzle