1.0 Binary Rejected - Help to understand the mistakes, please!

Hi,

It's my second app trying to send. The first one was approved without big problems.

Now I've sent my new app twice and got the same reply from the reviews. (see below)

The first one had only one checklist.
Now I put 3 checklists with around 50 items inside each one. Some of them with commenting.
How can it be minimum functionality?
Also about the In-App Purchase message:
I mentioned when sending the app that there's no in-app purchase.
There's only link for external websites courses. Nothing is happening inside the app.
It's self promotion only. The app is about my tools created for photographers, as are the external links for my courses.
How can I fix it for the approval?


This is the public link for testing: https://testflight.apple.com/join/g53BAPOi
Below the message from Apple:


From Apple

Guideline 3.1.1 - Business - Payments - In-App Purchase

We noticed that your app or its metadata provides access to external mechanisms for purchases or subscriptions to be used in the app, which does not comply with the App Store Review Guidelines.
Next Steps
To resolve this issue, please remove the account registration links and any other fully qualified links to your site that could indirectly provide access to these mechanisms, such as links to web pages for support, FAQs, product or program details, etc.
In-App Purchase
It may be appropriate to revise your app to use the in-app purchase API to provide content purchasing functionality.
In-app purchase provides several benefits, including:
- The flexibility to support a variety of business models.
- Impacting your app ranking by consolidating your sales to one app rather than distributing them across multiple apps.
- An effective marketing vehicle to drive additional sales of new content.
For information on in-app purchase, please refer to the following documentation:
In-App Purchase for Developers
In-App Purchase Programming Guide
For step-by-step instructions on in-app purchase creation within App Store Connect, refer to App Store Connect Help.

Guideline 4.2 - Design - Minimum Functionality

We found that the usefulness of your app is limited by the minimal amount of content or features it includes.
Next Steps
We encourage you to review your app concept and incorporate different content and features that are in compliance with the App Store Review Guidelines.
We understand that there are no hard and fast rules to define useful or entertaining, but Apple and Apple customers expect apps to provide a really great user experience. Apps should provide valuable utility or entertainment, draw people in by offering compelling capabilities or content, or enable people to do something they couldn't do before or in a way they couldn't do it before.