Optimizely CMS Pendo integration (editor module)

I'm trying to integrate the Pendo into the admin/editor part of the CMS system. To do that I have to add small js snippet to the page simmilar to google analytics. https://support.pendo.io/hc/en-us/articles/360046272771-Developer-s-Guide-To-Installing-the-Pendo-Snippet

What would be the best approach to do that? I tried doing that from the custom module initialization, but it looks like sometimes the code is not properly executed.

The important thing I have to pass Id/email of the current user to that script.