Oh goodness, I have been on the lookout for a peony fragrance for a BN friend for 3, no 4 (!) years and we still have not found what we are looking for.
The closest to nature, the truest peony is Ava Luxe Peony, I am not sure about its the availability where you are or on Etsy. It starts intoxicatingly floral with acidic pink peony undertones and then goes too powdery on me (no, I am not against powder in my fragrances, but here I feel it is slightly out of context). Serena, if you are reading this and planning to reformulate this, please make it a tad sweeter, would you?
Another contender would be Histoiries de Parfums Vert Peony which I have also tried and find acceptable but not very true to the real flower. Available through many etailers, one of them is Beauty Cafe.
BTW, this BN friend likes Yves Rocher Pour Desir de Peony that I have had a chance to try just recently -- a far cry from Yves Rocher discontinued Peony scent that I used to buy back in the early 90s.