Is It Possible to Cast a Spell on Someone If You Don't Know Their Names? asked a Quora use

As far as I'm aware, spells are unable to target a single individual because they are unable to determine your identity. The person who formulates them and then concentrates his attention on you spiritually is a spell caster, astrologer, or call him a psychic, "depending on what area of the world you hail from." You will get spells in this manner. So long as the healer is aware of who you are, he won't need your involvement in casting spells for you.