This module can only search in pages and posts. Add the following code to functions.pho to add other post types. The highlighted text is the slug of the post type that should be added to the search sources.

<https://intercom.help/elegantthemes/en/articles/3030197-how-to-enable-products-and-other-post-types-in-divi-s-search-module>

// START custom sources for Divi search module
function custom_remove_default_et_pb_custom_search() {
remove_action( 'pre_get_posts', 'et_pb_custom_search' );
add_action( 'pre_get_posts', 'custom_et_pb_custom_search' );
}
add_action( 'wp_loaded',
'custom_remove_default_et_pb_custom_search' );
function custom_et_pb_custom_search( $query = false ) {
if ( is_admin() || ! is_a( $query, 'WP_Query' ) || !
$query->is_search ) {
return;
}
if ( isset( $_GET['et_pb_searchform_submit'] ) ) {
$postTypes = array();
if ( ! isset($_GET['et_pb_include_posts'] ) && ! isset(
$_GET['et_pb_include_pages'] ) ) {
$postTypes = array( 'post' );
}
if ( isset( $_GET['et_pb_include_pages'] ) ) {
$postTypes = array( 'page' );
}
if ( isset( $_GET['et_pb_include_posts'] ) ) {
$postTypes[] = 'post';
}
/* BEGIN Add custom post types */
[$postTypes[] = 'product';]{.mark}
[$postTypes[] = 'project';]{.mark}
/* END Add custom post types */
$query->set( 'post_type', $postTypes );
if ( ! empty( $_GET['et_pb_search_cat'] ) ) {
$categories_array = explode( ',', $_GET['et_pb_search_cat']
);
$query->set( 'category__not_in', $categories_array );
}
if ( isset( $_GET['et-posts-count'] ) ) {
$query->set( 'posts_per_page', (int) $_GET['et-posts-count']
);
}
}
}
// END custom sources for Divi search module
Code language: PHP (php)