As Tetiana mentioned, how this is typically done in Creatio is by creating a configuration web service that you call from your client-side js code. It's actually one of my favorite parts of Creatio and makes for a very powerful development experience and allows you to keep the UI very quick by passing things between the client and the server and performing operations on the server rather than the client. Along with the Academy article Tetiana shared, I also have a write up of how to create a configuration web service and call it from client-side code here: https://customerfx.com/article/creating-a-web-service-and-consuming-it-…
