Stride UI: Custom UI Library element not visible in UI Editor

[HuangMiu]

I’m trying to create a reusable UI element with a UI Library in Stride.

According to the official documentation, UI Library root elements should be draggable into a UI Page from the UI Editor’s library panel.

What I did:

1. Created a new UI Library asset.
2. Opened the UI Library.
3. Added a root element, a Canvas.
4. Added child elements under it, such as two ImageElement.
5. Saved the UI Library.
6. Opened my UI Page.

Problem:
I can’t see my custom UI Library element in the UI Editor library panel, so I can’t drag it into the UI Page.However, I can see UserLibraries in Stride's tutorial project "GameMenu".So I'm wondering if I've missed any steps.

[HuangMiu]

My bad. You can only see it after naming the element.