Hi @pauluccio, thanks for your query. If you wish to integrate gaze (or dwell) to click within your own custom application, then you can do so via the Tobii Core SDK which you can download @ https://developer.tobii.com/consumer-eye-trackers/core-sdk/
with sample applications included which demonstrate the syntax to do so which you can find on github @ https://github.com/Tobii/CoreSDK
If however, you refer to using the eye tracker directly as a consumer then gaze (or dwell) to click is not a feature that is included with the Tobii Core Interaction Software as the device is intended to work alongside the mouse and keyboard, not necessarily replace them.
However, there are a number of third party applications, that may allow you to achieve this such as Xcessity (http://www.xcessity.at/) & the Microsoft offering as included with Windows 10 (https://support.microsoft.com/en-us/help/4043921/windows-10-get-started-eye-control)
Kindy have a look at the links I have sent and don’t hesitate to get in touch again should you have any further questions or comments.