Get text(if visible) returns the text if visible, what will it return if not visible?
It will not return anything, the step will pass anyway and the test will proceed to the next step.
Only if there is text will it return it and save it as output (if you enter a parameter at this step) if it does not - it remains empty.
if the element is not visible, the step also will pass with this message:
As you can see, this step will not fail the test ever and it will only take the text if the element exists and the text also there.