As mentioned in another thread, we're running into issues in getting the OneTrust cookie preference center to properly disable Munchkin. Rather than a fully automated, plug-n-play solution, OneTrust is more or less just a cookie scanning and categorization solution. There is still some custom dev work required to get it to properly enable/disable cookies like Munchkin. And part of the custom dev work involves slightly modifying the Munchkin js code on pages where it's served up. We've succeeded in this on our web site - where the script is fully exposed. The issue is on Marketo landing pages, where the script is served automatically behind the scenes. There's no way to modify it. Is there a way to disable the default script and, instead, replace it with our custom script? I've already reached out to support and they said there's nothing that can be done. I'm curious if that's truly the case.
There are various ways. The more secure is changing it at the template level or include in the template some links to external JS files that you store in a controlled place.
Bu if you really want to add some JS directly in a guided LP, this post might help: Best way to add a script in a guided landing page
But that doesn't work for Munchkin.
The way to manage Munchkin is here: https://blog.teknkl.com/conditionally-loading-munchkin-on-marketo-lps-for-gdpr-related-policies/