From the overview page for Adobe Draw:
If you're working on an iPad, iPad Pro, or iPhone, tap the shapes icon and select any App Shape, or Capture Shapes saved in your CC Libraries.
Place two fingers inside the shape to move it anywhere on the page or rotate it. Pinch inside the shape to enlarge or reduce its size.
You can draw around an App Shape to trace it with a brush, or double-tap inside the shape to stamp it. Note: You can only stamp, but not trace shapes added from CC Libraries.
I'm using Adobe Draw on an iPhone, there's no shape icon that I can find. Is the overview wrong?
link to page:
That feature is not yet in Draw for iPhone (that's an error in the tutorial).... but it's coming. Very soon.