Custom Wordpress Plugin Not Saving Settings - php

Question

I'm working on my first custom WP plugin and I'm trying to register a setting using the Settings API. I've followed a number of guides, and I've successfully created an admin menu page with the section and field defined in the plugin, but the single setting (in the code its fbm_lockout_updates) will not save, and no table in the database has been created for it.
EDIT: It is in fact in the options table. I was mistaken about that much. However, my options page still cant seem to update it, so I suppose my callback function is bad?
After trying a dozen things, I'm not sure where I'm going wrong. Here is the relevant code edited for brevity:
/* Create Menu */
add_action( 'admin_menu', 'fbm_config_menu' );
function fbm_config_menu() {
$page_title = 'Sample Plugin';
$menu_title = 'Sample Plugin Config';
$capability = 'manage_options';
$menu_slug = 'fbm_config';
$function = 'fbm_config_page';
add_menu_page(
$page_title,
$menu_title,
$capability,
$menu_slug,
$function
);
}
/* Register Settings and Fields */
function fbm_register_settings() {
register_setting( 'fbm_config', 'fbm_lockout_updates');
add_settings_section(
'fbm_restriction_section',
'Development Restrictions',
'fbm_restriction_callback',
'fbm_config'
);
add_settings_field(
'fbm_lockout_updates_field',
'Lockout Updates',
'fbm_lockout_field_callback',
'fbm_config',
'fbm_restriction_section'
);
}
add_action( 'admin_init', 'fbm_register_settings' );
/* Settings Callbacks */
function fbm_restriction_callback() {
?>
<p><?php esc_html_e( 'Description of Setting Section', 'fbm_config' ); ?></p>
<?php
}
function fbm_lockout_field_callback() {
$setting = get_option('fbm_lockout_updates');
?>
<input type="checkbox" name="fbm_lockout_updates" value="0" <?php checked('1', $setting); ?> >
<?php
}
/* Load Admin Page */
function fbm_config_page(){
if ( isset( $_GET['settings-updated'] ) ) {
add_settings_error( 'fbm_con_messages', 'fbm_con_message', __( 'Settings Saved', 'fbm_config' ), 'updated' );
}
settings_errors( 'fbm_con_messages' );
?>
<div class="wrap">
<h1><?php echo esc_html( get_admin_page_title() ); ?></h1>
<form method="post" action="options.php">
<?php
settings_fields( 'fbm_config' );
do_settings_sections( 'fbm_config' );
submit_button( 'Save Settings' );
?>
</form>
<div>
<?php }
?>

Answer 1

In this case register_setting will save your data in wp-options table, take a look into it.
Recommended if you want your setting to be shown in the wordpress api use both admin and api hook
add_action( 'rest_api_init', 'bm_register_settings' );
add_action( 'admin_init', 'fbm_register_settings' );