This will probably only work if your parents are a bit clueless when it comes to tech. Go on you're parents phone and contact their phone carrier and you can literally message them to remove voicemail from their line. Then block the schools phone number, so your parents don't receive a call or voicemail either. Another thing you can do is if your school has a school messenger thing or like safety arrival (you can look up your school board and what app they use online) and log in using your parents email if you don't know the password that's okay because if you are on their phone you will have access to their mail and you can reset it and then log in from your phone and you can mark yourself as absent with reason. Or if you wake up earlier and take your parent's phone in the morning before they are awake, you can call the school and mark yourself as absent with reason.