That’s because you need to print your settings fields in Kaipo_menu_callback
, something like:
<?php
function Kaipo_menu_callback() {
?>
<div class="wrap">
<h2>Kaipo</h2>
<form action="options.php" method="post"><?php
do_settings_sections( 'kaipo_menu_page' );
settings_fields( 'kaipo_menu_page' );
submit_button();
?></form>
</div>
<?php
}
I would strongly suggest reading the settings API in detail.