Here is an example of how I created and implemented a simple shortcode, and added it to a page using divi-visual-builder (inside the text module).
Here I am assuming that you have a good experience of creating child themes and PHP language.
Included a PHP file in function.php of a child theme
Edit PHP file and paste the following code:
<?php
function custom_shortcode( $atts , $content = null ) {
$output = '<h1>This is a shortcode text</h1>';
return $output;
}
add_shortcode( 'custom_shortcode', 'custom_shortcode' );
?>
Call shortcode
Now call the short code from anywhere inside any page or post with following method.
PHP method
<?php echo do_shortcode('[custom_shortcode]'); ?>
or
Call in a text editor in a post, or page, using visual page builder
[custom_shortcode][/custom_shortcode]