Hi,
I just added below script after the ckeditor web block and get the default value as www.example.com in url
"
<script>
var waitCKEDITOR = setInterval(function() {
if (window.CKEDITOR) {
clearInterval(waitCKEDITOR);
CKEDITOR.on( 'dialogDefinition', function( ev ) {
// Take the dialog name and its definition from the event data.
var dialogName = ev.data.name;
var dialogDefinition = ev.data.definition;
// Check if the definition is from the dialog window you are interested in (the 'Link' dialog window).
if ( dialogName == 'link' ) {
// Get a reference to the 'Link Info' tab.
var infoTab = dialogDefinition.getContents( 'info' );
// Set the default value for the URL field.
var urlField = infoTab.get( 'url' );
urlField[ 'default' ] = 'www.example.com';
}
});
}
}, 1000);
</script>
"

Output:

Regards.