wcps_metabox_navs

function wcps_metabox_navs_20200516($team_settings_tab) {

    $current_tab = isset($_POST['tab']) ? $_POST['tab'] : 'general';
    $team_settings_tab[] = array(
        'id' => 'custom',
        'title' => sprintf(__('%s Custom','text-domain'),'<i class="fas fa-list-ul"></i>'),
        'priority' => 3,
        'active' => ($current_tab == 'custom') ? true : false,
    );

    return $team_settings_tab;
}

add_filter('wcps_metabox_navs', 'wcps_metabox_navs_20200516', 99);

Display nav content

add_action('wcps_metabox_content_custom', 'wcps_metabox_content_custom');

function wcps_metabox_content_custom(){
    $settings_tabs_field = new settings_tabs_field();

    $team_settings = get_option('team_settings');
    $custom_option = isset($team_settings['custom_option']) ? $team_settings['custom_option'] : '';


    ?>
    <div class="section">
        <div class="section-title"><?php echo __('Custom Tab', 'text-domain'); ?></div>
        <p class="description section-description"><?php echo __('Custom tab description.', 'text-domain'); ?></p>

        <?php

        $args = array(
            'id'      => 'custom_option',
            'parent' => 'team_settings',
            'title'       => __('custom option','text-domain'),
            'details'  => __('Write custom option details.','text-domain'),
            'type'    => 'text',
            'value'       => $custom_option,
            'default'     => '',
            'placeholder'     => 'Custom text here',
        );

        $settings_tabs_field->generate_field($args);

        ?>

    </div>
    <?php
}

View post on imgur.com