Adding Messenger Chat widget on WebDesigner?

Hi all,
I need to say I'm really ignorant on everything I'm about to say: I don't know about codes, HTML, CSS, Java or anything, I'm just trying to figure out what to do to complete my website.
So, I wanted to add the Messenger Chat widget on my website (I'm using Web Designer Premium) and I got the HTML code Facebook give to add on my website. I was told to insert the code on the end of every body of the pages I wanted the widget on, but I can't figure out how to do it on WebDesigner.
Can't open the html in the program, and it's quite complex for me open the html directly on an editor, so I tried alternatives.
One thing I thought I could do was to create an object like the famous rectangle and in its properties insert the code (I tried body, head and both) but it didn't work.
I've also tried to paste the code in the "body" of the "every page of the website" section, somewhere in the website properties, but didn't work either.
I know it can be hard to answer to someone who knows so little but I'm here trying to understand.
How can I do what I'm attempting?
If you need to know anything just ask.

Welcome to TalkGraphics

Placeholder is what I would recommend for inserting the script. You have already tried this. So my next question is have you published the page to the web? Often these scripts will not work in preview mode but need to be published.

Web Designer is not an HTML editor and so any manual/editing changes you might make to the HTML document will be overwritten the next time you publish. This is why Xara uses "placeholders" to insert the code/script every time you publish your page or site.

One of the other members will have to add to this if I am incorrect (which I more often than not am).

Cannot stand Facebook.

Guessing. The widget code is probably of two parts: a <DIV> and a <SCRIPT> (with possibly <STYLE>).

The <DIV> is a rectangle Placeholder HTML code (body).
The <SCRIPT>/<STYLE> is for the Page code (head).

The rectangle (<DIV>) is put anywhere on the page and this appears as your widget button.

Acorn

Ah, OK. To clarify. To add the Page code to Head, in the Web Properties > Page section, click on the HEAD button and paste the code as Acorn suggests in there.

Remember to click Apply.