ITR/BIR for small business owners

Hi! Question lang for home-based online sellers who average sales per month is below 20k,need pa po i-register sa BIR?

Asking because I need an ITR for visa application. I am also a freelance VA and I work remotely kaya wala din pong ITR ma provide since my clients are based abroad. I used to work sa company before pandemic, but that was way back 2020.