Dual national - which passport(s) to scan for OWP application

[steelfisherman]

Hi, for OWP application I need to scan all pages of my passport. But I am a dual national and I have two passports from two different countries.
My question is, do I only need to scan the passport that I am using for that OWP application, or do I have to scan the passports for both of my nationalities?
Thanks a lot!