my snapchat randomly un downloaded itself and when i try to down load it back it’s making me sign into a whole different icloud that used to be used on tia phone but when i put the password it’s making me send a code and everything else

Any app download is tied to the Apple ID that was open at the time it was downloaded. If you have changed to a different Apple ID account you will have to delete the app, restart your phone, make sure you are logged in to the Apple ID that you want to use with the app, and download it again. As it is a free app this should cost anything, although you will still need a valid payment method in your account to download it.