Do I need to do it in properties or script it?
You go to the propertiies, go under "Text" and click textscaled. LOL
In the Explorer, locate the text. Then go to properties, find "TextScaled" and check it. This will make it so that the text automatically fits :)
I also think that you could do this:
local text = script.Parent -- change this to your text text.TextScaled = true
I hope this helps!