If you don’t see the pop-up menu, you may need to enable Markup. Choose Apple menu
Sketch a shape using a single stroke.
If your drawing is recognised as a standard shape, it’s replaced by that shape; to use your drawing instead, choose it from the palette that’s shown.
Draw : Drag the highlight where you want. To resize it, use the blue handles.
Text Attach photos, PDFs and more in Notes on Mac