In Abiogenesis, ""how did an RNA"" came from amino acids (product of non-living substance)?

It isn't known. There are a variety of hypotheses, and some propose that there was a more general protein-nucleic acid hybrid that eventually segregated into discrete proteins and nucleic acids. The question of "genes first" where the first molecules had distinct units or "enzymes first" where increasingly complex catalysts (e.g. iron-sulfur or polyphosphate) start things off.