By Elementor Templates Kit, we are refering to: https://sonaar.io/templates-for-elementor/
To import the templates:
Step 1 – Download the templates kit file at https://sonaar.io/login (Under My Account > Downloads)
Step 2 – Login to your WordPress dashboard.
Step 3 – Make sure Elementor Page Builder plugin is installed and activated. To install it, go to WP-Admin > Plugins > Add New and search for Elementor.
Step 4 – Import the Elementor Kit by going to WP-Admin > Elementor > Tools > Import/Export Kit > Start Import
Step 5 – Your imported template will now be displayed in your Templates list in WP-Admin > Templates
Step 6 – To use and insert templates into the page builder, read this article from Elementor Documentation: https://docs.elementor.com/article/60-library