ActiveDEMAND won't allow just any script to run inside the platform while logged in as this presents a major security risk. Thus ActiveDEMAND will automatically strip out any scripts you embed in the block builders.
To embed a script on a landing page, you can either embed the script on the row
Or on the Page script tag. The script will not run in the builder, but it will run the live page. If you want a custom script created for you, our development services team would be happy to do it for you!