Code Block for Google Maps showing 'Code Removed'

Hello, Can someone please tell me what I am doing wrong?  I am trying to embed a custom Google map to my page.  I've pulled the embed code from Google and pasted it in the code block but all my Squarespace is showing is 'Code Removed'  Not sure what I'm doing wrong.  Here is the Google Map embed code;

<iframe src="https://www.google.com/maps/d/embed?mid=1Zu3Kukeeg0esd7wpsbkFqnH711iYew0&ehbc=2E312F&noprof=1" width="640" height="480"></iframe>

Thanks in advance. 

Thanks for the quick reply.  That's what I read somewhere, but on the squarespace support page it says every plan supports HTML code block. It says just JavaScript or iframes are unsupported in the personal plan. Is this inaccurate?

Never mind I just realized I answered my own question, the HTML code from the Google map is an iframe HTML, I overlooked that in the code .   Thanks for your help!