Help! Apple rejecting my app

Hey all. I have a web app where users pay an yearly fee for subscribing. They get access to all the features once they subscribe. Now we want to launch a mobile app for subscribed users on ios and android. We built the app with a login screen and the subscribed users can use the same credentials they used on the website they can use it on the mobile app as well.

Our idea is that since the users already paid for the website subscription, they do not need to pay for the mobile app. When we submitted to Apple, they keep rejecting it stating "Your app accesses subscriptions purchased outside the app, but the subscriptions are not available to purchase using in-app purchase. The paid digital content, services, or subscriptions included in or accessed by your app must be available for purchase using in-app purchase."

I am not sure why do I need to force my users to pay for the app if they have already paid for my subscription features on the web. I am just displaying the same content on the mobile app.

Help! Does anyone know how to go about getting this app approved on apple?

Cheers.