"self-certification" and "tax issues"

I've been getting emails to do my self certification and tax information forms for almost the entire year of 2020, which continue to become a problem even after I've sent my self certification in three or more times so far. It doesn't help that I'm a) a university student with no car and barely any income and b) not the person with permissions over my account. Every notification has to go through my parents before I get them, making the process 10 times more exhausting because I don't pay tax in the first place.