Hello @lizbiout!
Thank you for contacting us.
I was reading your previous conversation, and I understand it.
In this case, I will need you to please read this post so you can learn how to set a Featured Image via the default WordPress screen: https://www.wpbeginner.com/beginners-guide/how-to-add-featured-image-or-post-thumbnails-in-wordpress/
If, after doing this, the process keeps failing; since you mentioned you recently acquired Elementor Pro, please open a ticket via your my.elementor.com account.
WordPress.org rules state that commercial products are not supported here.
Lastly, at Elementor, we currently only offer support in English. So, for further requests, please translate your messages first.
I hope this can help you.
I’m closing this conversation.
Regards.