Javascript to show only last 4 of number

Use this script:
     $('#NextButton').click(function () {
var textEntry ="";
var replaceText="*";
var x=textEntry.replace(/\\d(?=\\d{4})/g,replaceText);
Qualtrics.SurveyEngine.setEmbeddedData('vMasked',x);
});

declare vMasked embedded variable before the question where this script is added.

Thanks Appzk.
In order for this to work, I believe the code has to appear in a question block that appears prior to where the text will be displayed.
My survey is a single page, is there a way to write and display the embedded variable on the same page?

Add this script in a descriptive type of question before your page and add a page break.
Auto advance this question.
Keep both of this in one block.