Do I have to enter 25% in all three percentage boxes(premium, advanced payment of PTC and SLCSP) if I was a dependent on my parents insurance, 4 people on the same policy

I was a dependent on my parents market place insurance, but not a dependent on their tax returns. both my parents, my sister and I were on the same policy. Under allocation of policy amounts, should I enter 25% in all three boxes- namely premium percentage, advanced payment of PTC percentage and SLCSP perencentage? or is the SLCSP percentage box left blank? I read that somewhere that SLCSP percent box is usually left blank. is that true for everyone?