Could Not Get Field Value

Hi, I have a simple settings page with the following setup:

add_filter( 'mb_settings_pages', 'limit_settings_code' );

function limit_settings_code( $settings_pages ) {
    $settings_pages[] = [
        'menu_title'  => __( 'Limit Settings', 'bbcm' ),
        'option_name' => 'Limit Settings',
        'position'    => 25,
        'style'       => 'no-boxes',
        'columns'     => 1,
        'icon_url'    => 'dashicons-welcome-widgets-menus',
    ];

return $settings_pages;

}

add_filter( 'rwmb_meta_boxes', 'credit_limit_code' );

function credit_limit_code( $meta_boxes ) {
    $prefix = '';

$meta_boxes[] = [
    'title'          => __( 'Credit Limit', 'bbcm' ),
    'id'             => 'credit_limit',
    'settings_pages' => ['limit_settings'],
    'fields'         => [
        [
            'name'     => __( 'Credit Limit Amount', 'bbcm' ),
            'id'       => $prefix . 'credit_limit_amount',
            'type'     => 'text',
            'required' => true,
            'columns'  => 4,
        ],
    ],
];

return $meta_boxes;
}

=================

With the code above, I want to get the value of the settings in function.php but rwmb_meta() return null.

According to this page, https://support.metabox.io/topic/code-not-working-with-updated-version/

I also tried get_option():
$test1 = get_option( 'limit_settings' )['credit_limit_amount'];
$test1 is still null.

WordPress v5.9
Meta Box v5.5.1
Meta Box AIO v1.15.5

Please help.