To create a fixed element, select a layer or Hotspot and check the Fix position when scrolling option in the Prototyping section of the Inspector. Alternatively, choose Prototype › Fix Layer Position when Scrolling in the menu.
This is handy when you want to fix a row of tabs at the bottom of an app design, or have a floating button on a website, for example.
How to create scrolling Artboards
If you want to create a prototype with scrolling elements, you’ll need to choose an Artboard preset, or create a Custom Preset, and resize its height. If you don’t use a Preset and draw a custom Artboard instead, your prototype won’t scroll and will appear zoomed out in the app, on the web app and in Mirror, our iOS app.
To create a scrolling prototype from an Artboard preset, select your preset and change its height on the canvas. When you do this the preset name in the Inspector changes to include the word Resized.
To create a custom size Artboard preset that scrolls, then choose Create Custom Size at the bottom of the Inspector. Confirm your Artboard’s dimensions and name, then change its height on the Canvas. Like regular presets, its name in the Inspector will change to include the word Resized.