How to implement google captcha verification via java?

Question

Java

Hello, there was a need to implement a captcha using a third-party application (so that it would be a person, not a bot), but you need to take the captcha from another site, and send the result, respectively, to the same site. This is necessary in order to write a more convenient application (service) for receiving / sending data.
I would also like to know if the site can restrict the creation of such services? If yes, how can you find out?