If you are trying to limit the home page to display only posts that have a featured image, you’ll need to modify the post query being used to generate that page.
With a premium theme it may be best to consult the theme’s author first, to see if there is a configuration option or other easy method built-in to do what you want.
Otherwise, you may be able to create a child theme that modifies that query via a filter (perhaps using has_post_thumbnail(), see https://developer.wordpress.org/reference/functions/has_post_thumbnail/) or much less desirably, by modifying the logic in the premium theme itself.