I want to upload my game on the TIC-80 Website but it requires an .tic file and I don't know how to do that and the wiki and internal help doesn't say how to do that, so how do I export my game to a .tic file?

type command "folder" on TIC-80, then you will see system file of TIC-80 and find your game there

Just to add...

If you created and saved your game using TIC's editor it'll already be in .tic format (unless you saved it as something else eg .lua). If you did save it as a .lua or other file, just load it and save it as a .tic from the console, eg load mygame.lua -> save mygame.tic

As MFauzan says, typing 'folder' from TIC's command line will show you where all your carts are saved/exported.

For more help with 'export' see: https://github.com/nesbox/TIC-80/wiki/Console

...or just type 'export' in the console :D