Problem getting my background image to scale

Hey guys, I created a 1920x1080 image to use as my background in the game, didnt spend much time on it but would still like it to scale. I set the canvas scaler to have everything scale to the screen size, and I believe it all worked except for my image It would adjust the width, but not the height, so you can see my panels and stuff where my background is supposed to be. Any way around this? I dont care too much about how it looks atm, but for future reference, what is my background size supposed to be to fit all resolutions no problem?

https://docs.unity3d.com/Manual/HOWTO-UIMultiResolution.html

This link should explain everything to ya. Just look for this subtitle:
Scaling with Screen Size

You need to set the anchor-points in all the corners!