A couple of weeks ago. Now there is an update but I do not know how to update my game. 

Hello there, you should have been issued a link or a key when you bought the game, simply use that to access the game and download the new version :)

Let me know if it works!

All I had to do was go to my itch./io library and it let me update from there. Thanks for the help. Game is a lot of fun.

Awesome, glad to hear it worked! And thanks for posting the solution so others can use it if they run into this too. :)