Actually, my doctor friend told me that oxytocin is responsible for the 'let-down' reflex (milk flow), but you also need hormones like prolactin to actually produce the milk. If you are looking into induced lactation for adoption, you must consult an endocrinologist or lactation expert for a safe protocol.
When we talk about hormones, it's always best to be very careful. My mother always said that our body's natural cycle is very sensitive, so please don't try any medications or hormone therapy without consulting a proper gynac first.
I am not very sure about the medical side of this, but it sounds like a very delicate process. It is best to speak to a doctor or a specialist who can guide you gently and safely.
I totally understand how deeply you might be wishing for this beautiful bonding experience. While oxytocin helps release the milk, you will need proper guidance from a doctor to safely induce lactation. Sending you so much warmth and love on this journey.