Depends on your schools policy, I'm not doing it and am allowed in. Make your own choice, if you don't want it don't get it as it's an option, not a mandate.
There are reasons to refuse, the tests are inaccurate (false negatives and false positives) and multiple peer reviews have shown that- Birmingham, Liverpool, Scottish unis and accuracy decreases with training e.g. a healthcare professional sample had much more accuracy than students. You don't "have" covid if asymptomatic, you're just carrying it. "Having" it is actually being ill, in which case any sensible person would stay at home.
However I'm biased as I disagree with testing and realistically there's no harm in doing it but please know you are allowed to refuse and no-one should be questioning your refusal.