For Mobile:
Step 1: Find "Games" Folder in your internal Storage/External Storage, in Games Folder Find com.mojang > minecraftworlds folder.
Step 2: Open Downloaded World and find WOwnX3J7AAA= folder, just copy that World (WOwnX3J7AAA=) folder and paste here(minecraftworlds) folder.
For PC:
Search minecraftworlds folder from search option. and copy WOwnX3J7AAA= folder in minecraftworlds folder.
