Problem in getting my apps created with Thunkable to be accepted in the Apple Store

First app

Hello everyone. I have a problem in getting my apps created with Thunkable to be accepted in the Apple Store, I can not pass the review! I share with you the links of my apps so if someone can help me! Thank you very much Francesco

ps.
I copy and paste what Apple wrote to me and my answer (the screenshots are not a problem I change them, but I think my app is too simple in its structure and has, perhaps, a few content).

Do you have any advice in telling me where I’m wrong and how could I correct my apps? Thanks so much

From Apple:

2. 3 Performance: Accurate Metadata
2. 5 Performance: Software Requirements
4. 2 Design: Minimum Functionality

Guideline 2.3.3 - Performance - Accurate Metadata

We noticed that your screenshots do not sufficiently reflect your app in use.

Specifically, your 12.9-inch iPad and 5.5-inch iPhone screenshots do not display the actual app in use.

Next Steps

To resolve this issue, please revise your screenshots to ensure that they accurately reflect the app in use on the supported devices. For iPhone, you need a set of 5.5-inch display screenshots and for iPad, you need a set for 12.9-inch display. This set will be scaled appropriately down to other device sizes when viewed on the App Store in each territory.

Note that 5.8-inch display assets for iPhone X are optional and don’t scale down to other devices sizes. Screenshots that include iPhone X layout features like rounded corners or sensor housing should only be used for the 5.8-inch display.

Resources

For resources on creating great screenshots for the App Store, you may want to review the App Store Product Page information available on the Apple developer portal.

Please ensure you have made any screenshot modifications using Media Manager. You should confirm your app looks and behaves identically in all languages and on all supported devices. Learn how to use Media Manager to add custom screenshots for each display size and localization.

Guideline 2.5.1 - Performance - Software Requirements

Your app uses the “prefs:root=” non-public URL scheme, which is a private entity. The use of non-public APIs is not permitted on the App Store because it can lead to a poor user experience should these APIs change.

Continuing to use or conceal non-public APIs in future submissions of this app may result in the termination of your Apple Developer account, as well as removal of all associated apps from the App Store.

Next Steps

To resolve this issue, please revise your app to provide the associated functionality using public APIs or remove the functionality using the “prefs:root” or “App-Prefs:root” URL scheme.

If there are no alternatives for providing the functionality your app requires, you can file an enhancement request.

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.

I just received this same comment from the Apple Store Review team. My app calls a public URL (api.particle.io) to get an IoT device to do something. I don’t know how to work around this particular issue, as I assume it’s related to the code Thunkable creates. HELP!!!