Elementor

Go to pages. Then select your desired page & click Edit with Elementor.

Or, Go to edit page. Then, click Edit with Elementor.

also from front-end

Now, Add Slider Revolution 6 from elements.

Go to Select Module to show your modules. You can also add shortcode of a slider to add that slider on your page.

Select your desired Slider.

Here is the view of Slider.