Nobita is excited for a summer trip to a tropical island using Doraemon's Anywhere Door. However, in his haste, he accidentally drops the door's special key — a small, golden, magnetic device — into a sewer grate while running away from Gian, who wants him to join a grueling baseball practice.
After a muddy chase through underground pipes, Nobita gets the crow to cough up the key by offering it a piece of candy from Doraemon's pocket. Gian, impressed by Nobita's determination, calls off practice.
August 23, 2019
If we assume you are referring to the (Japanese original order) and the episode commonly labeled as Episode 44 of Season 17 in international listings, here is a plausible piece — a fictional yet realistic plot summary for such an episode, written in the style of the show: Title: The Anywhere Door's Lost Key (どこでもドアの鍵なくしちゃった)