App includes an update button
Your app includes an update button or alerts the user to update the app. To avoid user confusion, app version updates must utilize the iOS built-in update mechanism.
We’ve attached screenshot(s) for your reference.
Please remove the update feature from your app. To distribute a new version of your app, upload the new app binary version into the same iTunes Connect record you created for the app’s previous version. Updated versions keep the same Apple ID, iTunes Connect ID (SKU), and bundle ID as the original version, and are available free to customers who purchased a previous version.