Is it his responsibility to help me with financial issues?

I’m 17 & a junior in high school. I never met my real dad, he left to Spain when I still was in the womb. He didn’t know my mom was pregnant, he asked her & she said no. After he arrived in Spain, he found out about me. He used to call me & text me saying he’d send me gifts but he never did. At one point I hated him for lying but I matured and decided to forgive because I didn’t need that grudge burdening my relationship with him nor my life. Now he lives in Brazil & my mom is telling me to ask him for money because he never sent me any throughout my 17 years of life and I’m also his responsibility. It’s only so much my mom can do, we’re struggling with payments. The thing is that she is married. My stepdad helps me as much as he can & since I never met my real dad, i feel kind of iffy about asking him for money. We do talk often & I update him a lot on my life but I’ve never asked him for anything & the only time I’ve shamed him for “owing me” anything had to do with the parental care he never gave me & how sad it was growing up seeing my friends have that bond with their dads that I always desired. What do y’all think?