The7 Post Types
Custom The7 post types depend on “The7 Elements” plugin, which can be installed under Dashboard -> The7 -> Plugins section. There is a built-in Portfolio post type, which can be enabled under Dashboard -> The7 -> My The7 (fig. 1). You can also manage Portfolio slug (URL) there.
If you need more post types, you can enable deprecated built-in The7 post types (not recommended) – fig. 2.1. Or create custom new ones (recommended) using The7 Post Type Builder – fig. 2.2.
You can find more info regarding The7 Post Type Builder here.
Elementor in Custom Post Types
In order to enable Elementor for a specific post type, please refer to Elementor -> Settings -> General (fig. 3) and select appropriate check-boxes: