Living with grandparents and dad

I live with my grandparents since 2017 they receive child benefit for me, my dad now also lives with us he is on benefits ,i am astranged from mother no contact ,since 2018, i need to apply for student finance for september 2023, i am dependant on grandparents do i apply for finance useing there details as they receive chid benefit or my dad on universal credit benefits which do not include me, or do i judt get letter from my teacher who knows my circumstances, thank you Lana

Thank you i was panicking as read somewhere you need proof your estranged ,and when it said household income ,i thought as grandparents get child benefit they had to be on application .my dad is single so no partner and he is on benifits , but we live in my grandparents house.