Activation email not working

Hello everyone!
I tried to create a registration form based on the instructions below, but the activation link is not sent to the user based on the instructions provided.
The email sending system works on an external SMTP basis, but so far there have been no problems with it.
Could you help me, what could be the reason for this?
Here’s the help
Tutorial


1

Hello. If you’re still having an issue with this, it may be caused by asynchronous (background) feed processing. You can use the gform_is_feed_asynchronous filter to disable background feed processing for the User Registration Add-On:

Use this code:

add_filter( 'gform_is_feed_asynchronous', function ( $is_asynchronous, $feed, $entry, $form ) {

    if ( rgar( $feed, 'addon_slug' ) === 'gravityformsuserregistration' ) {
        $is_asynchronous = false;
    }
 
    return $is_asynchronous;

}, 10, 4 );

This is PHP code that can be added to your theme functions.php file, or you can use a plugin such as this one to keep the code separate from the theme: Code Snippets – WordPress plugin | WordPress.org

Please see this article for additional information on placing PHP snippets: Where Do I Put This Code? - Gravity Forms Documentation

Let us know if you continue to have trouble after that.