Mautic is deleting the "onclick" on the landing pages

Your software
My Mautic version is: 2.16.2
My PHP version is: 7.1.33
My Database type and version is:

Your problem
My problem is: I’m using a checkout widget on the buttons on my landing page using this tutorial ( however, when saving the code in the Mautic editor, it deletes automatically onclick=“Eduzz(‘Widget’, { id: 123456 }, this);” inside the .

These errors are showing in the log:

Steps I have tried to fix the problem: