I can not understand why the parameters are not saved?

Question

WordPress

Why are the settings not saved?

The specific code where the fields are created and saved:

spoiler

public function function_settings_fields() {
        register_setting('export_google_sheets_settings','id_document', 'absint');
        add_settings_section('export_settings_section_id', '', '', 'export_google_sheets' );
        add_settings_field('id_document','ID документа (Гугл таблицы)',array( $this, 'function_get_settings' ),'export_google_sheets', 'export_settings_section_id',
            array( 
                'label_for' => 'id_document',
                'class' => 'id_document-class', 
                'name' => 'id_document', 
            )
        );

        /*********************************************************** */  
        
        register_setting('export_google_sheets_settings', 'id_document','absint');
        add_settings_section('export_settings_id_list_section_id','', '', 'export_google_sheets' );
        add_settings_field('id_list','ID листа (Гугл таблицы)',array( $this, 'function_get_settings' ), 'export_google_sheets', 'export_settings_id_list_section_id', 
            array( 
                'label_for' => 'id_list',
                'class' => 'id_list-class', 
                'name' => 'id_list', 
            )
        );
    }
    public function function_get_settings($args) {
        $value = get_option( $args[ 'name' ] );
 
        printf(
            '<input type="text" min="1" id="%s" name="%s" value="'.$value.'" />',
            esc_attr( $args[ 'name' ] ),
            esc_attr( $args[ 'name' ] ),
            absint( $value )
        );
    }

Full code:

spoiler

class export_sheets {
    public function __construct() {
        add_action('admin_menu', array( $this, 'function_settings' ) );
        add_action('admin_init', array( $this, 'function_settings_fields' ) );
        add_action( 'admin_notices', array( $this, 'settings_update_notice' ) );
    }

    public function function_settings() {
        add_menu_page('Настройка экспорта информации','Экспорт Google Sheets', 'manage_options', 'export_google_sheets', array( $this, 'export_sheets_menu_callback' ), 'dashicons-admin-generic', 150 );
    }
    public function export_sheets_menu_callback() {
        echo '<div class="wrap">
            <h1>' . get_admin_page_title() . '</h1>
            <form method="post" action="options.php">';
        
                settings_fields( 'export_google_sheets_settings' ); 
                do_settings_sections( 'export_google_sheets' ); 

                submit_button(); 
        
            echo '</form>
        </div>';
    }
    public function function_settings_fields() {
        register_setting('export_google_sheets_settings','id_document', 'absint');
        add_settings_section('export_settings_section_id', '', '', 'export_google_sheets' );
        add_settings_field('id_document','ID документа (Гугл таблицы)',array( $this, 'function_get_settings' ),'export_google_sheets', 'export_settings_section_id',
            array( 
                'label_for' => 'id_document',
                'class' => 'id_document-class', 
                'name' => 'id_document', 
            )
        );

        /*********************************************************** */  
        
        register_setting('export_google_sheets_settings', 'id_document','absint');
        add_settings_section('export_settings_id_list_section_id','', '', 'export_google_sheets' );
        add_settings_field('id_list','ID листа (Гугл таблицы)',array( $this, 'function_get_settings' ), 'export_google_sheets', 'export_settings_id_list_section_id', 
            array( 
                'label_for' => 'id_list',
                'class' => 'id_list-class', 
                'name' => 'id_list', 
            )
        );
    }
    public function function_get_settings($args) {
        $value = get_option( $args[ 'name' ] );
 
        printf(
            '<input type="text" min="1" id="%s" name="%s" value="'.$value.'" />',
            esc_attr( $args[ 'name' ] ),
            esc_attr( $args[ 'name' ] ),
            absint( $value )
        );
    }
    function settings_update_notice() {
 
        if(isset($_GET[ 'page' ]) && 'export_google_sheets' == $_GET['page'] && isset($_GET[ 'settings-updated' ]) && true == $_GET[ 'settings-updated' ]) {
            echo '<div class="notice notice-success is-dismissible"><p>Настройки экспорта обновлены!</p></div>';
        }
     
    }
}

$export_sheets = new export_sheets();