How to open Safari's settings from web page on iOS 9.3+

Question

Here I find solution how to open Settings in iOS: How to redirect to ios settings in Safari use javascript in ios9

<input type="button" onclick="redirect()" value="Redirect">
<script>
    var redirect = function() {
        window.location.href = "prefs:root=Settings";
    }
</script>

But there is some problems with this solution on my iPhone 6s plus 9.3.2(13F69): - this solution doesn't work on my particelar iPhone, but work on iPhone 6s - link to prefs:root=Safari doesn't work

So I've got 2 questions:

1. How could I find out why this solution doesn't work on my particular phone?
2. How could I open Safari's in Settings app?

Answer 1

window.location.href = 'App-prefs://prefs:root=Settings';

Try this, Working in iOS 13