How to download reCAPTCHA from an external server?

Question

reCAPTCHA

Good day.
Available : A script that receives an xml file as input, parses it, collects a structured json array and sends it with a POST request to a third-party server.
Everything worked well, but recently reCaptcha was added to submitting the form. Now, along with all the data, the code of the solved captcha should be transmitted.
The task is not to bypass the captcha, but to load it and solve it on my server before sending the post request.
When trying to load captcha ( https://www.google.com/recaptcha/api2/anchor?k=........ ) from my server, a js error occurs:

Failed to execute 'postMessage' on 'DOMWindow': The target origin provided does not match the recipient window's origin)

Answer 1

no way in php.
phantomjs and similar to use and solve captcha on the fly when the site is open.