found only photo of no contact ex being held by their dad as a baby

long time lurker, first time poster

i (25) have been going through boxes in my parents house to make space for a relative moving into my old room. i found a polaroid picture of my ex (25), who i have not spoken to in over 4 years, being held by their father as a baby. i assume that this is the only picture, aside from pictures taken of the polaroid, of this very important life event. i feel wrong holding onto it and would feel worse throwing it away.

i really do not want to have to talk to them again, relive that time in my life, or refresh the connection. i am making healthier choices for myself now and have been in a serious relationship going on 4 years. they have messaged me several times since our breakup, checking in and attempting to get back in contact with me, i've been ghosting them for years. i don't hate this ex, just don't want them in my life anymore, but don't know how to

go about getting this polaroid back to them without having to talk to them, or worse, meet up in person. we do not have any mutual friends, i do not have their family's contact information, i do not know where they live now (no mailing), what should i do???

tldr; found a polaroid of my no contact ex being held as a baby, assumedly the only picture of said event, how do i get it back to them with as little interaction as possible?