Currently, the best app for use on iPhone with iOS 14 and above is FoXray. To enter the config code on your iPhone, first install the FoXray app via the Apple Store, then follow the steps below.

1- Copy the code provided by us completely.

2- Open the FoXray app and click on the icon:

3- If asked, select Allow paste and click on the newly created connection's icon to establish your connection.