Calling and verifying from javascript

Hello, I’m new to sweet Captcha, so far I like the design, it was easy to implement. My question is that since my site submits it’s forms with a javascript event handler, Sweet is not validating. Is there a way to verify that it’s been answered correctly with javascript. I would like to verify this before the POST contents are verified with PHP.

https://www.ads-software.com/plugins/sweetcaptcha-revolutionary-free-captcha-service/