Assalamu alaikum, I have a disagreement with my father about reciting aloud in fajr, maghrib, and isha prayers. He thinks it’s wajib, but I say it’s just sunnah. Who’s correct and what’s the daleel?

Just to clarify, I meant when we pray alone, not in jama’ah. My father is pretty firm that for fajr, maghrib, and isha, you have to say everything loud, even if you’re by yourself. I heard it’s only a sunnah act, not something you’re sinning over if you miss it. Can someone explain which view is stronger and why? Jazakum Allahu khairan.