To download a wallpaper, open it and press and hold to save it as an image. You can also take a screenshot of the wallpaper.

Here are the steps in more detail:
1. Open the wallpaper you want to download.
2. Press and hold on the wallpaper until a menu pops up.
3. Select "Save as Image" from the menu.
4. The wallpaper will be saved to your device's gallery.

You can also take a screenshot of the wallpaper by following these steps:
1. Open the wallpaper you want to take a screenshot of.
2. Press the power button and the volume down button at the same time.
3. The screenshot will be saved to your device's gallery.