Honest feedback needed: Is my free Invoice Generator actually useful?

Hi Product Hunt! 👋

I'm a student developer and I recently built Zyncro Invoice Generator. The goal was simple: make a tool that doesn't require a signup or monthly fee just to send a PDF invoice.

I'd love your brutal honest feedback on the UI/UX. What is the one feature that is a "must-have" for you in an invoice tool?

Thanks for your support!