Syntax error when adding custom code

I'm trying to add a widget in a block on the home page and when I insert the custom code it says "syntax error on line 1".

This is the code:
<script type="text/javascript" src="https://www.cqc.org.uk/sites/all/modules/custom/cqc_widget/widget.js?data-id=1-8373894706&data-host=https://www.cqc.org.uk&type=location"></script> 

Can anyone tell me what the syntax error might be please?
Many thanks for your help.

Try this:

<script type="text/javascript" src="//www.cqc.org.uk/sites/all/modules/custom/cqc_widget/widget.js?data-id=1-8373894706&data-host=www.cqc.org.uk&type=location"></script> 

Hi Ziggy, I get the same error message unfortunately

Sounds to me like you are trying to enter the code in Design > Custom CSS. Only CSS can go there.

What you have is HTML and needs to go in a code block or other location that accepts HTML.