If your emojis are not showing up when you type on your iPhone, it could be due to a few reasons. Firstly, make sure that predictive emojis are turned on. To check if the predictive function is enabled, head to Settings > General > Keyboard > Keyboards > Add a New Keyboard, then find and select Emoji. Now, make sure the Predictive function is enabled. If predictive emojis are turned on and still not working, try restarting your iPhone or updating your iOS to the latest version.