uninstall.php

<?php

/**
 * CC Smart TOC Uninstall
 *
 * @package CC_Smart_TOC
 */

if (!defined('WP_UNINSTALL_PLUGIN')) {
    exit;
}

/**
 * Delete data only if user explicitly opted in.
 *
 * Option name: cc_toc_delete_data_on_uninstall
 * Value: '1' or 1
 */
$ccstoc_delete_data = get_option('ccstoc_delete_data_on_uninstall',1);

if ((string) $delete_data !== '1') {
    return;
}

/**
 * Plugin options detected from plugin settings.
 */
$ccstoc_option_keys = [
    'cc_toc_delete_data_on_uninstall',

    // Settings (cc_toc_settings group)
    'cc_toc_positions',
    'cc_toc_post_types',
    'cc_toc_numbering',
    'cc_toc_auto_insert_mode',
    'cc_toc_scrollspy_offset',
    'cc_toc_scrollspy_offset_side',
    'cc_toc_side_position',
    'cc_toc_close_on_click_desktop',
    'cc_toc_handle_align',
    'cc_toc_min_headings',
    'cc_toc_title_label',
    'cc_toc_default_state',
    'cc_toc_numbering_style',
    'cc_toc_max_level',
    'cc_toc_custom_css',
    'cc_toc_exclude_terms',
    'cc_toc_exclude_posts',
    'cc_toc_custom_mode',
    'cc_toc_custom_h2',
    'cc_toc_custom_h3',
    'cc_toc_custom_h4',
    'cc_toc_custom_h5',
    'cc_toc_frame_style',
    'cc_toc_theme_color',
    'cc_toc_custom_apply',
    'cc_toc_custom_colors',
    'cc_toc_custom_frame_style',
    'cc_toc_fix_threshold',
];

  foreach ($ccstoc_option_keys as $ccstoc_key) {
   delete_option($ccstoc_key);
    delete_site_option($key);
}