Following is the format of the path:
{___grecaptcha_cfg.clients[0].RY.W.callback("results");} this one is updated dynamically every one in a while.
This is the manual about how to setup it. You can follow it to check how it works.
We will consider to create a video for it in the future, please wait for the news.
Here is the simple video the programmer recorded.
https://drive.google.com/file/d/1wFydnAEMcMBCNHrV9h5mAfAj1kmm4Ttx/view?usp=sharing
Sorry the video is lost.
Follow the introduction we made above, then check if you can make it work. If you need help with the recaptcha, we can write the module for you with additional fee too, you can add this Skype(Chinasunny5) to talk about the details.