here's a script that allows you to put text in the center of a costume (and save that costume to the costume list) to create a button. Remember to change the pen color to the color you want the text to be.
I created this script because I wanted to create a bunch of costumes with text in the center of one costume. I didn't want to manually do it, so I created this. You don't have to put the add to (my costumes) block.