Add custom icon to header (navBarMaster) with action dropdown in Acumatica

Hi everyone,

I’m trying to customize the Acumatica UI by adding a custom icon to the top header area (the element with id navBarMaster).
 

My goal:

• Add a new icon/button in the header (similar to notification/user icons)
• When clicking the icon → trigger an action (e.g., show a dropdown or popup list of items)

What I’ve explored so far:

• Injecting JavaScript via MasterPages (e.g., FormDetail.master) → works but not safe for deployment
• Looking for a solution using Customization Project (C# / Graph / PXPage) instead of modifying core files

Questions:

1. Is there a supported way to extend the header (navBarMaster) via Customization Project?
2. Can this be done purely with C# (Graph/Page customization), or is JavaScript required?
3. Are there any recommended patterns for adding global UI elements (like a notification bell)
   
   Any guidance or best practices would be greatly appreciated.

   Thanks!