Connection Line tool will allow you to link objects on the board. This is helpful for building diagrams and flowcharts.
To create a line, select Connection Line on the toolbar or press L on your keyboard, click an object and drag your cursor to another object. You can also select an object and click one of the blue dots around it to start drawing a link.
Specify arrowheads, line and stroke type, thickness, color etc. in the Connection Line menu:
To draw a straight horizontal, vertical, or diagonal line, hold Shift. To disable snapping to other objects hold Ctrl (Cmd).
Drawing a straight line and a standalone line
If you want to create a specific path for the line, you can do so by working with the blue bullet points on the line:
To remove extra bends and turns, simply click on the white bullet points.
Adding text labels
Each diagram item is meaningful, and the lines are not an exception. To establish clearer relations between objects on your boards use text labels.
Double-click any connection line or click +T in the context menu to start entering the text. Fix it horizontally or let the text follow line curves.
Adding a text label to the line