Resolves as YES if credible and verifiable sources, such as official statements by NATO or its member countries, international investigative bodies, or widely recognized media outlets, confirm NATO's direct involvement in the drone attack on PSKOV. Resolves as NO if credible and verifiable sources conclusively refute NATO's involvement. Resolves as NA otherwise.
1,000Creator is inactive, and there is little reporting on the matter of NATO's involvement at all (likely because it's not considered very credible), so whilst there of course aren't sources confirming NATO's involvement, neither are there any "conclusively refuting" it.
We have Latvia and Estonia denying involvement:
https://www.newsweek.com/russia-pskov-airport-strike-not-estonia-nato-member-says-1823464
But the creator required a "conclusive refutation", and not just denials, in order to resolve NO.
Therefore in accordance with the description, I'm resolving N/A.