Desperate, Nobita uses the Small Light to shrink himself and search the sewer. Inside, he encounters a lost baby crow who has swallowed the key, thinking it was a shiny pebble. Nobita befriends the crow, but Gian and Suneo — also shrunk — chase him, thinking Nobita is faking the crisis to avoid practice.
The group uses the Anywhere Door to go to the island — but Doraemon accidentally sets it to the North Pole. The episode ends with everyone shivering as a penguin waves at them.
It sounds like you're asking for the plot of Doraemon Season 17, Episode 44. However, please note that episode numbering varies significantly between different versions of the anime (e.g., 1979 series, 2005 series, and regional broadcasts like USA or India). doraemon season 17 episode 44
Without the key, the Anywhere Door is stuck on its last destination: the inside of Shizuka's bathroom (much to everyone's embarrassment). Doraemon panics, explaining that the spare key is at the 22nd-century repair shop, and delivery will take 24 hours.
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. Desperate, Nobita uses the Small Light to shrink
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)
August 23, 2019
Anywhere Door, Small Light, Take-copter (briefly).