Probably nothing.
The ImagePicker tries to request READ_EXTERNAL_STORAGE on Android 13+ with the compiled app (APK). With Companion, correctly READ_MEDIA_IMAGES is requested, but this is not declared in the Companion APK either.
Back to APK:
Since READ_EXTERNAL_STORAGE no longer exists on Android 13+, an error message is of course displayed: “The permission READ_… has been denied. Please…”. I therefore used the ActivityStarter (android.intent.action.PICK), which I generally prefer to the ImagePicker.
So the ImagePicker only works up to Android 12. This is of course another bug with Kodular. I already gave up counting more than 3 years ago (while I was still a moderator). 