Among Us has been updated to version 2021.3.13, which adds along other things the airship map.

Here are the full patch notes:

• The 4th map, and the biggest one yet 
• New tasks including jewel polishing, emptying trash (wow fun), and more 
• The ability to pick the room you start in 
• All new areas to explore (or get murdered in) 
• Improved mobility with ladders and moving platforms 
• New free hats including a heart pin, angry eyebrows, unicorn head, rubber glove, and more! 
• Inspired by our other game, The Henry Stickmin Collection

Source: Nintendo Everything