As the blog says, invisible reCAPCHA is meant to prevent bot. So, if your script or tool is identified as a bot, obviously Google will sense that and give you challenge.
The reCAPCHA challenge is installed to prevent automation. So, for you to do automation, you should closely work with the dev team and find out a way to avoid the challenge. This is the ideal way.
Yet, we could overcome "I'm not a robot" checkbox using AutoIT and sometimes using Robot classes from Java in one of our projects. But, most of the time we used Selenium or ProtractorJS. So, we were required to execute our code on the grid. So, we got limited here. Hence ultimate solution was to work with the dev team and remove challenge on necessary environments.