Astra uses the WordPress Hooks API to insert actions throughout the theme. This plugin allows you to hook your custom content, shortcodes, or JavaScript code into various hook locations.

Once installed, you will see a new tab in the Customizer. See screenshots for more information.

To see all of the available hooks in Astra, visit this page.
http://developers.wpastra.com/theme-visual-hooks/

Need to add dynamic content with various conditions? Please consider the Astra Pro Addon. Custom Layouts module in Astra Pro Addon offers functionality so you can add dynamic content (PHP Code) easily.

Astra Hooks