wordpress : Add section to existing page

add-section

<?php
// Register and define the settings
add_action('admin_init', 'boj_myplugin_admin_init');

function boj_myplugin_admin_init(){
	//You still need to whitelist this setting, with register_setting() . 
	//Omitting this step would make WordPress ignore the setting when submitting the form. 
	register_setting(
		'privacy',
		'boj_myplugin_options',
		'boj_myplugin_validate_options'
	);
	add_settings_section(
		'boj_myplugin_options',
		'My Plugin Settings',
		'boj_myplugin_section_text',
		'privacy'
	);
	add_settings_field(
		'boj_myplugin_text_string',
		'Enter text here',
		'boj_myplugin_setting_input',
		'privacy',
		'boj_myplugin_options'
	);
}
/**
 * register field plugin
 */
/*function boj_myplugin_admin_init(){
	register_setting(
		'privacy',
		'boj_myplugin_options',
		'boj_myplugin_validate_options'
	);
	add_settings_field(
		'boj_myplugin_text_string',
		'Enter text here',
		'boj_myplugin_setting_input',
		'privacy',
		'default'
	);
}*/
?>

settings-page.php

<?php
// Register and define the settings
add_action('admin_init', 'boj_myplugin_admin_init');

function boj_myplugin_admin_init(){
	//You still need to whitelist this setting, with register_setting() . 
	//Omitting this step would make WordPress ignore the setting when submitting the form. 
	register_setting(
		'privacy',
		'boj_myplugin_options',
		'boj_myplugin_validate_options'
	);
	add_settings_section(
		'boj_myplugin_options',
		'My Plugin Settings',
		'boj_myplugin_section_text',
		'privacy'
	);
	add_settings_field(
		'boj_myplugin_text_string',
		'Enter text here',
		'boj_myplugin_setting_input',
		'privacy',
		'boj_myplugin_options'
	);
}
/**
 * register field plugin
 */
/*function boj_myplugin_admin_init(){
	register_setting(
		'privacy',
		'boj_myplugin_options',
		'boj_myplugin_validate_options'
	);
	add_settings_field(
		'boj_myplugin_text_string',
		'Enter text here',
		'boj_myplugin_setting_input',
		'privacy',
		'default'
	);
}*/
?>