Guide

1. Head over to the bottom section of your Figma design canvas and then click 'Shape Tools'.

2. Choose 'Line' from the list of options.

3. Following that, use your mouse cursor to draw a line anywhere around the canvas.

4. Once done, go to the Stroke section under the Design tab and click the 'Advanced Stroke Settings' icon.

5. Next, click the 'Stroke Style' menu.

6. Choose 'Dash' from the list of available options.

7. Subsequently, specify your desired 'Dash', 'Gap', 'Dash Cap', and 'Join'.

8. After that, click anywhere around the canvas to apply the changes.

9. Finally, a dotted line will be created and added to your Figma design canvas.