I found a utility for uploading .ipa to apple store connect
xcrun altool --upload-app -t ios -f "$IPA_PATH" -u "$APP_STORE_CONNECT_USERNAME" -p "$APP_STORE_CONNECT_PASSWORD"
But before upload, it should be signed using apple certificates. I'm lost here. for android, we have some parameters about the key store but for iOS I can't find any.
Can someone help me in the right direction?