Replace woo revews - create a relationship between 2 posts after submitting form

Hello
I have a form on the product page that creates a cpt post “review” and I want to create a relationship between after submitting proforms
so basically I replace woo revews but I can’t get it to work

Here is my code

add_action('bricks/form/custom_action', 'add_relationship_review_product', 10, 1);

function add_relationship_review_product($form) {
    $form_fields = $form->get_fields();
    $form_id = $form_fields['formId'];

    // Check if the form ID is for the specific form you're targeting
    if ($form_id !== 'qosxpx') {
        return;
    }

    // Get the submission ID from the special variable {{live_post_id}}
    $submission_id = '{{live_post_id}}'; // Use {{live_post_id}} as submission ID

    // Make sure submission ID is present
    if (empty($submission_id)) {
        return; // Exit if submission ID is empty
    }

    // Add relationship between product and review submission
    MB_Relationships_API::add(get_queried_object_id(), $submission_id, 'product_review', $order_from = 1, $order_to = 1);
}

how i can get the $submission_id