Expandable textbox as the main component on the screen

Question

I have a screen that its main component is a text box. Users add the text by pasting it in the text box and then click on the button, which results with an image generated in the screen. it is the main component because the user enters text many times, each time to generate a different image.

My question is: most of the time the text is not so long, but there are times the text is long and the user needs to see the text they entered. I thought of an expandable text box that the user can pull down to see all text when needed? and what do I do with the button? Leave it in its place?

Answer 1

There's a script for an auto-expand textbox where the user doesn't have to touch any element on the screen, beyond the submit button that can remain static.