Featured Image Slider option is there in all our Pro/Premium Themes only and it's not there in our Free Themes. For free themes, you can add in featured page slider. For this check out our other video • How to Add Featured Page Slider
This image slider is an independent image slider, where you can upload image of your own choice and size, link it to any URI that you want, add in title and content as per your need.
1. First go to your WordPress Dashboard and then Appearance - Customize - Featured Slider
2. in "Enable Slider on", you need to select either Homepage or Entire Site as per your need.
3. In Select Slider Type, you need to select the slider type as Featured Image Slider
4. Then upload images, add in title, content and link as per your need and click on "Save & Publish"