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You can achieve this by following the below steps.
Slider Settings are located in Appearance >> Customize >> Dazzling Options >> Slider Options
To enable slider tick checkbox and you will see that two no options will appear “Slider Category” and “Number of slider items”
Select category from dropdown to use for slider
Now select number of slides to be used in slider (newest Posts from that category will be used)
Make sure you have Featured Images uploaded and added for those Posts and also set the slider category to the posts.