The sketch about SOLID principles should be in read only mode, so it isn’t possible to change it.
But I guess you’re talking about the drawing on an empty canvas, aren’t you? In this case you may choose the tools (i.e. Pen, Text, Rectangle, Ellipse, etc) by clicking on the central black button on the bottom of the page. This is for the mobile. For the desktop all of the tools should be immediately visible for selection without two clicks.
