Unsplash features over 6 million curated photos and illustrations from a generous community of 375,000 contributors. All images can be used for free for commercial and non-commercial purposes, without permission from or attributing the photographer or Unsplash.

Click the Media icon on the editor toolbar or press I on your keyboard. In the left sidebar, select Unsplash and search for a keyword. Click on the media you want to use and it will be added to your slide. You can also drag it on top of an image on your slide until a purple outline appears to replace it.