Help, creating a UI with a button.

Hi, I'm a beginner in unity. And it's the first time I ask for help in the forum. I'm doing my first serious program, and I want to make a button that creates Textbox , so the user can complete it. Something like the plus button of the Event Trigger, which adds more lines to place commands. Well I want to add textbox for the user to complete. thank you very much.

Quaris