How to fix ‘Call to undefined function do_settings()’ error?

I am writing my first plugin and to access/save options I follow codex.wordpress.org/Creating_Options_Pages I basically copied the example from ‘See It All Together’ in a separate file mhomepage_admin_menu.php

The main code of the plugin goes like

if ( is_admin() ){ // admin actions
    add_action('admin_menu', 'add_plugin_admin_page' );
    add_action('admin_init', 'register_mhomepage_settings' );

} else {
  // non-admin enqueues, actions, and filters
}

function register_mhomepage_settings() { // whitelist options
  register_setting( 'mhomepage_option_group', 'left_right_margin_option' );
  register_setting( 'mhomepage_option_group', 'top_margin_option' );
  register_setting( 'mhomepage_option_group', 'include_comments_option' );
}  

function add_plugin_admin_page($plugin_name) {
    add_menu_page( 'mHomePage', 'mHomePage', 'manage_options', 'mhomepage/mhomepage_admin_menu.php', '', '', 6 );

}

and the beginning of mhomepage_admin_menu.php looks like

<div class="wrap">
<h2>Your Plugin Name</h2>

<form method="post" action="options.php">
    <?php settings_fields( 'mhomepage_option_group' ); ?>
    <?php do_settings( 'mhomepage_option_group' ); ?>
    <table class="form-table">

I have to questions

• Q1: how to fix the error?
• Q2: what is the correct file name in <form method="post" action="options.php">? Is that mhomepage_admin_menu.php?