if like i brought it and like it needs to update how do i like download it again? do i need to pay another time?
If you have the itch.io launcher, it should be able to be updated through that.
If not, at the top of the page while signed in, there's a "you own this game" banner with a "download" button. Re-download and extract it, overwriting the previous files, and it should be updated. Just make sure you hit "yes" to the overwrite option when it asks.