Guides
https://freemius.com/blog/how-to-make-money-sell-elementor-templates-template-kits/
Envato: https://help.author.envato.com/hc/en-us/articles/360038151251
Envato: https://help.author.envato.com/hc/en-us/articles/360038229332-How-To-Create-A-Template-Kit
Elementor: https://elementor.com/help/template-library/
Marketplaces
https://www.templatemonster.com/elementor-templates.php
https://creativemarket.com/search/elementor-template-kit
https://www.etsy.com/search?q=elementor%20template%20kit
Envato’s ThemeForest and Envato Elements