Hi @hube2 , thank you very much for your time.
If I understand correctly, I should paste this code on my function.php, and then where says ‘relationship_field_name’ I should write the relationship field from where I’m interested to get the thumbnail image? Because if it’s the case, it’s not working for me.
Then the image should appear in “featured image” on my “print-size” cpt without doing a thing, isn’t it?
