Hi @beyondtool,
I hope you are well today and thank you for your question.
You can use pages in the slider by using the child theme solution shared in the following topic
https://colorlibsupport.com/t/slider-for-pages/#post-33351
To use custom post type in the slider you have to customize the function sparkling_featured_slider added in the functions.php file of shared child theme.
Best Regards,
Movin