If KakaoTalk is not working on your iPhone, here are a few things you can try:

  1. Check your internet connection: Make sure your iPhone is connected to the internet, either through Wi-Fi or mobile data.
  2. Update the app: Check if there is an update available for the KakaoTalk app in the App Store and download it if there is one.
  3. Restart the app: Force quit the KakaoTalk app and reopen it. To force quit an app on an iPhone with Face ID, swipe up from the bottom of the screen and hold until the app switcher appears. Then, swipe up on the KakaoTalk app. On an iPhone with a Home button, double-click the Home button and swipe up on the KakaoTalk app.
  4. Restart your iPhone: Try restarting your iPhone to see if it resolves the issue.
  5. Delete and reinstall the app: If none of the above steps work, try deleting the KakaoTalk app from your iPhone and reinstalling it from the App Store. Keep in mind that you may lose your chat history and settings if you do this.

If none of these steps work, you can contact KakaoTalk customer support for further assistance.