how to download (for iphone)

i had accidentally deleted tiktok and I don't know how to get it back. i can't change my country/ reigon beacuse i have store credit that i don't know how to bypass. which means every time i try to change it, it says i cant change stores because of that store credit. if you have gone through this or saw a video on how to redownload it, i would greatly appreciate it.