Perfect on iPad not so much on iPhone, help?

We built a children’s story book app/game, it looks great on iPad, covers the whole screen but on iPhone theres black borders to the right and left. Is there a way to make it look perfect on all devices instead of doing separate builds?

Use a Canvas Scaler, set to Scale with Screen Size, and Match Width or Height with a 0.5 factor.

https://docs.unity3d.com/Manual/script-CanvasScaler.html

Thank you, ill look into this.