An iFrame (called my_iframe and which has an external domain inside when the user submits myform: https://hpp.sandbox.addonpayments.com/pay) is in an iFrame in my web; as can be seen in the code.
My_iframe returns (when the user is done with what it does inside it) a message with information. However, the eventlistener type message (underlined and in bold) never receives it. I have used window.open('https://www.google.com', '_blank'); to visually know if any message is received: however, it never gets called when the inner iframe send the message.
Why am I not receiving the message? And, what can I do to get it?
RELEVANT CODE (inside wix html component):
This is how it visually looks (here you can see both iFrames -the inner one and the html component from wix-, and the form submit button):