Check this link and follow through, in particular the part where mando posts the links - Legacy Pack for GOTY in hitman 3
I added to the fix posted in the link above. I had to attempt to purchase the Hitman - Legacy Pack to get the H1 content to work. I’m not sure if this will help you as you say you don’t own the H1 GOTY edition and I show ownership for H1 GOTY and the H1 GOTY Legacy Pack. Could not access H1 content until I got access to the discontinued Hitman Legacy Pack (not GOTY Legacy Pack).
Hope this helps you (and others)