why does php shows a notice when trying to access an associative array through one of the key? is it possible to disable it for this case?-ThrowExceptions

lets suppose the example I am using is the following

     $fields = array('Name','Age','Grade');

     $studentsDictionary = array(array('Name'=>'Mark','Age'=>15,'Grade'=>19),
                     array('Name'=>'John','Age'=>15,'Grade'=>11),
                     array('Name'=>'Tom','Age'=>15,'Grade'=>10));

    for($i =0;$i<sizeof($studentsDictionary);$i++)
    {
        for($j=0;$j<sizeof($fields);$j++)
        {
            echo $studentsDictionary[$j][$fields[$i]].' ';
            echo array_keys($studentsDictionary)[$j][$i].' ';
        }
        echo $nl;
    }           

I have 2 way to access the key of the associative array one is creating an array which contains the string keys for said associative array and the other I found was using array_keys(arrayName)[index][key_index] (like using [i][j] but backwards indexing…)
so every time I use the 2nd method it shows

Notice: Trying to access array offset on value of type int in
C:\xampp\htdocs\phptest\index.php on line 75

can I disable such notice for this case?

 $fields = array('Name','Age','Grade');
 $studentsDictionary = array(array('Name'=>'Mark','Age'=>15,'Grade'=>19),
                 array('Name'=>'John','Age'=>15,'Grade'=>11),
                 array('Name'=>'Tom','Age'=>15,'Grade'=>10));

for($i =0;$i<sizeof($studentsDictionary);$i++)
{
    for($j=0;$j<sizeof($fields);$j++)
    {
        echo $studentsDictionary[$i][$fields[$j]].' ';
        echo array_keys($studentsDictionary[$i])[$j].' ';
    }
    echo $nl;
}