A simple and lightweight package that encapsulates PencilKit's PKCanvasView putting it inside a SwiftUI context with CanvasView and includes a fully-fledged drawing UI - CanvasDrawingView!
Copy the github link (in the green code button's dropdown) and add as a dependency to Xcode, using Swift package manager. Go to project settings > Dependencies and press Add. Now paste the github link into the search field and add this package.
You may either use the CanvasView directly for fine-grained control over its appearance, or use the CanvasDrawingView. The CanvasDrawingView coontains the CanvasView inside a navigation stack and adds relevant buttons, to show/hide the tool picker, save / share the drawing and delete the drawing. Therefore, if you want to customize these buttons, put CanvasView inside your own UI.
If you want to display a user's PKDrawing in a SwiftUI view, I've included a DrawingView that accepts a PKDrawing and displays it. It manages the drawing's scale in the frame it is given.
For example, if the drawing was drawn at 50x100pt and the frame for this view was 300x600pt the drawing would be scaled up and become pixelated. The PKDrawing.image(from:scale:) method scales the drawing strokes up/down without making them pixelated so this is how my view works.
PKDrawing is one of the many things that you should be able to store in SwiftData that raises a SwiftData error due to an internal bug (I'm presuming).
The workaround to this is persisting the drawing's data in SwiftData (with the PKDrawing.dataRepresentation) and retrieving the actual drawing with PKDrawing.init(data:). This is the purpose of the DrawingModel.
It can only be used if you only want to store a drawing in SwiftData model.
the license for this package is, do whatever you want with it, you can sell, modify & redistribute it. Anything.