Formula milk

Hi. I'm a first time mom. My baby is 1yr and 4 months. Pero until now ayaw nya parin ng formula milk. I've tried a lot of milk already pero ayaw padin. What shall I do? Everytime na binibigyan ko sya ng formula milk, tinatapon nya lang or niluluwa nya. I have to go to school to finish my studies pero diko sya maiwan. What shall I do? Please help me. and thank you in advance