AppLovin uses the Apple search API for iOS and a third-party API (42matters) for Android. The solution depends on the platform of the app you are promoting.
iOS:
1. App Not available in the US
By default, we will search for apps based on the US AppStore. If your App is not available in the US, make sure to click the "App not available in the US AppStore?" button and select a country that the app is available in.
2. Wrong apps are showing up even though I'm using the exact name
Often times when an app's title uses words that are common in many other apps' titles, the Apple API will return the wrong results. In this case, the solution is to search for the developer name instead.
Android:
1. App was recently launched in the store
42matters can take up to 24 hours before the app shows up in their data set. Very occasionally they will miss an app entirely. If you app has been in the store for more than a day and it is not showing up, please email approval@applovin.com and be sure to include the Play Store URL for your app
2. My app consists of Unicode characters
Sometimes there are issues with searching for apps with non-ASCII characters. This can often be resolved by searching for the app's package name. You can find this by looking at the 'id=' parameter in the Play Store URL for the app