Add Related Posts in Elementor

By using the Posts Widget in the Single Post Template, you can display Related Posts by terms. Terms include Categories, Tags, Types, and Formats.

1. Create or Edit your Single Post Template
2. From the Widgets Panel drag a Posts Widget to the desired location
3. In the Source drop down options select Related
4. Include By – Term
5. Terms – Choose by Categories, Tags, Type, or Format
6. Set the Exclude Terms if needed
7. Publish or update your Single Post Template

Additional Resources:

https://developer.wordpress.org/themes/functionality/post-formats/

https://developer.wordpress.org/themes/basics/categories-tags-custom-taxonomies/