How to get node from other canvas in same scene Cocos Creator 3.5

I am using Cocos Creator 3.5.0.

On one of my scene I have 2 canvases, let's say below is the hierarchy:

StartScene
|- MainCanvas
   |- Background
|- UICanvas
   |- TextLabel

I have this script called StartScene_Manager.ts and I put/assign it into the MainCanvas. On the script I want to access TextLabel from UICanvas. I have tried all of these:

const testText = find("UICanvas/TextLabel");
..
..
const testText = find("../UICanvas/TextLabel");
..
..
const testText = find("/../UICanvas/TextLabel");

None of those works, testText always null.

Anyone can give me insight about this ?