Why is my app still getting rejected despite no errors on my demo store?

[lramhudda]

The app is working on my demo store. I am not getting any issues but the Shopify team said the app has an error.
 

Required changes

We were redirected to an error page when attempting to install your app. Please test your app's installation on a development store using OAuth before resubmitting. Review this example of what the required installation flow looks like and see this screencast for context on your app.

Use OAuth to ask for scope permissions immediately after merchants add your app. Check and troubleshoot your app's OAuth by reinstalling your app on your test store using this method. See this screencast for context on your existing install flow.

Can anyone tell me what to do next?
thank you very much

[paul_n]

Is this related to Shopify Flow at all?