When you add screens to a flow, they are automatically brought in based on their positions in the design file. Then, you can visually lay out your screens within the flow.

You can click and drag to move your screens around. Unlike a design tool, screens snap to a grid so that they can be easily aligned. You can also select multiple screens and move them by dragging them around.

Here's an example where the screens are laid out based on two different paths that a user can take: