Is it possible to add javascript to navigation menu item?

I've got some code to add in a javascript button that links to a pop up for booking appointments on Setmore.
I've been able to include on the page on the website with buttons and a custom image. I'm wondering if it's possible to add the jave script as an item on the Navigation menu?

This is the code that I have....

<script id="setmore_script" type="text/javascript" src="https://my.setmore.com/webapp/js/src/others/setmore_iframe.js"></script><a id="Setmore_button_iframe" style="float: none;" href="https://my.setmore.com/bookingpage/edd2a7ca-7880-49f5-9745-743237d2310b"><img src="https://alexandertechniqueeastkent.co.uk/wp-content/uploads/bookyourplacebutton.png" alt="Book your place with Alexander Technique East Kent using SetMore" border="none" /></a>

Thanks in advance for any advice on whether this is possible.