I would like to change Input sources when enter into URL input box, is that possible do that?
Hi Michael, and welcome to the forum!
In the Keyboard Maestro vernacular: a Trigger defines what event causes a Macro to execute its defined sequence of Actions.
In your case, I don't think entering into a URL input box can be a trigger. You can, however, use a Hot Key trigger to override and augment an app's existing keyboard shortcut.
For instance, Command+L in most browsers will enter the URL input box. You could create a macro that is triggered by Command+L when your browser is active, start with an action that actually sends Command+L so that you enter the URL input box, and then insert your other actions after that.
Let me know if I can clarify anything or if you have any other questions.
Good luck and have fun!