Its purpose is to disable your form submission button when the input is required and its value is false and enable the same when the required permission is set to true.
It can be set by using:
<button for-gc-input-name="YOUR-INPUT-KEY" gc-input-lock></button>
for-gc-input-nametells us which input should it listen to (you can have more than one input per page) and
gc-input-lockis the funcionality.