QR code component

What are you most proud of, and what would you do differently next time?

This is the first time I'm publishing code anywhere :)

What challenges did you encounter, and how did you overcome them?

Im not sure if my html is semantically correct.

What specific areas of your project would you like help with?

I really don't know how to control line of text. I used max-width: 25ch to limit lenght of text but I don't know if it is done right. Is h2 semantically appropriate for a component header?