8863 Refundable credit

I'm doing my taxes through TT and when I get to the 8863 form there seems to be a problem. I can't get the refundable credit for the AOTC even though I am under 24, live with my parents but fully support myself (earned income was more than one-half of my support, we split everything 50-50, and they don't claim me as a dependent), and I'm a full-time student (the box is not checked in line 7). Do I not qualify for it or am I missing to answer something in TT?