Upon clicking a Gutenberg button from custom lock screen Description section, user will be added to a CRM tag.

fluentcommunity-custom-waitlist-fluentcrm-tagging.php

<?php
/**
 * Add the user to a FluentCRM tag when a private-space request is submitted.
 */
add_action('fluent_community/space/join_requested', function ($space, $userId, $by) {
    if (!defined('FLUENTCRM')) {
        return;
    }

    // Space slug => FluentCRM Tag ID
    $spaceTagMap = [
        'start-here'     => 1,
        'jurassicninja' => 2,
    ];

    $spaceSlug = $space->slug;

    if (!isset($spaceTagMap[$spaceSlug])) {
        return;
    }

    $tagId = $spaceTagMap[$spaceSlug];

    $contact = FluentCrmApi('contacts')->getContactByUserRef($userId);

    if (!$contact) {
        $contactData = \FluentCrm\App\Services\Funnel\FunnelHelper::prepareUserData($userId);
        $contactData['status'] = 'pending';
        $contactData['source'] = 'fluent-community';

        $contact = \FluentCrm\App\Services\Funnel\FunnelHelper::createOrUpdateContact($contactData);
    }

    if ($contact) {
        $contact->attachTags([$tagId]);
    }
}, 10, 3);


/**
 * Make the custom Gutenberg "Join Waitlist" button submit the join request.
 */
add_action('fluent_community/portal_footer', function () {
    ?>
    <style>
        .fcom-waitlist-message {
            display: block;
            width: 100%;
            max-width: 720px;
            margin: 16px auto;
            padding: 20px 24px;
            border: 1px solid #d8e3ef;
            border-radius: 12px;
            background: #f7fbff;
            color: #26364d;
            font-size: 17px;
            line-height: 1.6;
            text-align: center;
            box-shadow: 0 5px 18px rgba(31, 41, 55, 0.08);
        }

        .fcom-waitlist-message strong {
            color: #142b4a;
            font-weight: 700;
        }

        .fcom-waitlist-error {
            margin-top: 12px;
            color: #b42318;
            text-align: center;
        }
    </style>

    <script>
    (function () {
        function getSpaceSlug() {
            if (
                window.fcom_current_community &&
                window.fcom_current_community.slug
            ) {
                return window.fcom_current_community.slug;
            }

            const match = window.location.pathname.match(/\/space\/([^/]+)/);

            return match ? match[1] : '';
        }

        function getCommunityName() {
            if (
                window.fcom_current_community &&
                window.fcom_current_community.title
            ) {
                return window.fcom_current_community.title;
            }

            return document.querySelector(
                '.fcom_space_title, .fcom_space_header h1, h1'
            )?.textContent.trim() || 'this community';
        }

        document.addEventListener('click', function (event) {
            const button = event.target.closest(
                'button, a, .wp-block-button__link'
            );

            if (!button || !/join\s+waitlist/i.test(button.textContent.trim())) {
                return;
            }

            event.preventDefault();
            event.stopPropagation();

            if (button.dataset.waitlistSubmitting === 'true') {
                return;
            }

            const spaceSlug = getSpaceSlug();

            if (!spaceSlug || !window.FluentCommunityUtil?.Rest) {
                return;
            }

            button.dataset.waitlistSubmitting = 'true';
            button.disabled = true;
            button.setAttribute('aria-busy', 'true');
            button.textContent = 'Submitting...';

            window.FluentCommunityUtil.Rest.post(
                'spaces/' + encodeURIComponent(spaceSlug) + '/join'
            )
            .then(function () {
                const communityName = getCommunityName();

                const message = document.createElement('div');

                message.className = 'fcom-waitlist-message';
                message.setAttribute('role', 'status');
                message.setAttribute('aria-live', 'polite');

                message.innerHTML =
                    "You've been added to the <strong>" +
                    communityName +
                    "</strong> waitlist. We'll notify you as soon as this community unlocks.";

                const buttonWrapper =
                    button.closest('.wp-block-button') ||
                    button.parentElement ||
                    button;

                button.style.display = 'none';
                buttonWrapper.appendChild(message);
            })
            .catch(function (error) {
                console.error('Waitlist request failed:', error);

                button.dataset.waitlistSubmitting = 'false';
                button.disabled = false;
                button.removeAttribute('aria-busy');
                button.textContent = 'Join Waitlist';

                const errorMessage = document.createElement('div');
                errorMessage.className = 'fcom-waitlist-error';
                errorMessage.textContent =
                    'Unable to submit your request. Please try again.';

                button.parentElement.appendChild(errorMessage);
            });
        });
    }());
    </script>
    <?php
});