Trigger an event when user makes a text input

Is there a way to trigger an event as soon as a user starts typing into an input text box? For example, I want a “Next” button to appear from hiding once a user has typed a single character.

The closest solution I can find is when a user changes the value of an input; however, this requires the user to click outside of the text box in order for the condition to be met. In my case, I want the trigger to happen as soon as the user types.

You can add a condition on the button “when input is focused > this element is visible”