Roll a dice using JavaScript in qualtrics

Hi all, I am new to using Java in qualtrics and I would appreciate your help.

I want to roll a dice once and to store the result as embedded data to use it later in the survey. The dice rolls well, BUT I CAN'T STORE THE RESULT. These are the steps that I followed.

1- In the beginning of the survey flow, I created a new field: result_matrix_embedded (I did not set it equal to any value)
2- This is what I wrote in the JavaScript of the question: I am using some code that I found online from Philip Tschiemer
Qualtrics.SurveyEngine.addOnload(function()
{
// Required for the callback functions to work.
var self = this;

// For our comfort, the common settings are predefined.
var value_set = [
{key:"1",probability:1},
{key:"2",probability:1},
{key:"3",probability:1},
{key:"4",probability:1},
{key:"5",probability:1},
{key:"6",probability:1}
];

var images = {
base_url:'https://www.descil.ethz.ch/projects/1305-SensQuest/dice/img/',
ext:'.png',
init: 'qmark1.png'
};

new Dice("dice1","throw1",{
possible_throws: 1,
value_set: value_set,
images: images,
result_callback: function(throw_nr,result_key){
Qualtrics.SurveyEngine.setEmbeddedData('result_matrix_embedded'+ throw_nr, result_key);
}
});
});

3- This is what I wrote in the HTML:
<strong>Are you ready to roll the dice?</strong><br />
<br />
If yes, roll the dice below by clicking on the button.
<br /><br /><br />
<script src="https://www.descil.ethz.ch/projects/1305-SensQuest/dice/dice.js"></script>
<div style="position:absolute; left:200px;"> <div id="dice1"></div></div>
<br /> <br /> <br />
<div style="position:absolute; left:179px;">
<button id="throw1">Roll dice</button> </div>

* This part works. I can roll the dice and it shows a value. Now, I want to store the result.
4- In another block I write, a text question: This is the result: ${e://Field/result_matrix_embedded}
And it doesn't show anything!. The result is not stored in the field. Qualtrics.SurveyEngine.setEmbeddedData() seems to be not working.
I tried many other JavaScript codes to roll a dice, but I never manage to store the result. If you happen to know any other way rather than this code, it would be highly appreciated!

Thank you!