If you are running tiktok ads on this campaign then you will need to provide an ad code, typically referred to as Spark Ads code. Instructions to find this are here
We refer to countries as tiers in ad targeting to help group them based on their economic status, consumer behaviour, and advertising potential.
Tier 1 countries typically have high purchasing power and strong digital infrastructure, so ads here are more expensive but more valuable.
Tier 2 and Tier 3 countries usually have lower ad costs but also lower average spending or conversion rates.