go to the app, look up the game, hit install and accept all the prompts. please dont spam. you can also ask these thing in the forums on the site or look in the replies here. just google it if you need to know so bad.
yes, its the same servers as the site we are on, the game is not posted here and is not posted there either, so you are requesting a download that does not exist. the main reason to have the itch app is for auto downloads and posting games you make. i assume you want to download the game from there since you cant from here, but it will be available here as soon as it is available on the itch app. hope this helps.