You can't draw arrows or highlight squares with a touch screen device. You would need a mouse or trackpad.
To add comments or select a focus move, you need to connect with a web browser, not an app.
On a touch screen device, press and hold a move to see a popup menu. Then you'll see an option to add a comment.
If you want a game to display a certain move when loaded, press/hold a move and select the "Set Focus" option.
Is there an article or something like how to make comments on games, how to draw arrows and highlight squares, and how make a board start with more than one move like the board starts out with 17. Bg6 Ke7,
Btw I’m on a iPad