The Pskov region of Russia is 800 kilometers from Ukraine's border. The drones Ukraine is using only have a range of 300 kilometers. Estonia borders Russia near the Pskov region. Either the drones came from somewhere other than Ukraine or something other than a drone was used in the attack.
Or maybe they had operatives inside Russia proper. The also used drones to hit an airbase over 700km away.
The question you should be asking is why are Russian air bases so poorly protected.
