expo: ERROR ITMS-90022: "Missing required icon file."

I get this error when trying to upload the app with the Application Loader built with expo:

ERROR ITMS-90022: "Missing required icon file. The bundle does not contain an app icon for iPhone / iPod Touch of exactly '120x120' pixels, in .png format for iOS versions >= 7.0."

How can I add these icons? I can’t seem to find it in the documentation. This is my app.json:

{
  "expo": {
   "name": "APK - Alkohol Per Krone",
   "icon": "./src/assets/logo/APK_512.png",
   "version": "1.0.0",
   "slug": "alkohol-per-krone",
   "sdkVersion": "20.0.0",
   "orientation": "portrait",
   "ios": {
     "bundleIdentifier": "com.apk.alkoholperkrone"
   },
   "android": {
     "package": "com.apk.alkoholperkrone"
   }
  }
}