The "creden" value is null like the following "creden": null, and other one is the following "creden": { "uName": "5xxxxxxx" }, set the below condition for them and it works!

   if ($response[$i][$j]{creden} ne "" ) {
                
                $responsuname = $responsetextall[$i][$j]{creden}{uName
+};
                
                } else {
                 
                 $responsuname = "No UNAME";
            }
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