How to make letter

How do you get letters to cut out can’t find an app for it

Enter desired text in Easel, set carve to Outline and either outside path/on path or inside path.

Inkscape. Create a text box, change object to path, save as SVG, import into Easel.

Both are correct.
If the font you like is already in Easel that is a very easy way to get them done.
If the font you like is not in Easel but you have the font installed on your system then Inkscape is a wonderful way to import your text into easel. you can then use the Exploder app as needed as well.