hello! you can add it to babel.config.js. you should have one in your project that looks roughly like this: expo/babel.config.js at 896a29e5abbe285c7cba89a03053696216dd2793 · expo/expo · GitHub
also note that you should only do this in production by using the env config as you can see in that blog post. note that you should not change from babel-preset-expo to 'module:metro-react-native-babel-preset' - that is not required and will cause problems for you