Is it possible to disable a single recaptcha?

I’m maintaining a website for a client that has about 4 different forms.
Since they were getting a lot of spam, recaptcha was implemented to reduce it, which worked!
However, now I’m creating some custom functionality, for which I need a hidden form that I fill and submit using some custom javascript.
So that means that this hidden form also has to have recaptcha, however I need to either turn only this one off, or get around it somehow.
So my question is, is there any way, or workaround to disable only this one recaptcha, have it pre-filled or something?
Thank you!