image fit all sizes? (URGENT)

Unity Engine
1

I have this image already in the project, am working with a resolution of 1080x1920 and it looks well… no blue vessels the thing is when i change the aspect ratio, it doesn’t fit to the changed size, all my UI is with a canvas scaler so it fits.

My question is:
how can i make my image fit to every portrait mode?

2

Do you use anchors in your UI elements?.

Here you have some useful texts:
Redirecting to latest version of com.unity.ugui
Redirecting to latest version of com.unity.ugui
Redirecting to latest version of com.unity.ugui
Unity UI Tutorial: Canvas and Scalability - Cat Trap Studios