testplugin.php

<?php
/**
 * Plugin name: Test plugin
 * Description: Test settings page TinyMCE use
 */

function wporg_settings_init() {
    register_setting( 'wporg', 'wporg_options' );
 
    add_settings_section(
        'wporg_section_developers',
        __( 'The Matrix has you.', 'wporg' ), 'wporg_section_developers_callback',
        'wporg'
    );
 
    add_settings_field(
        'wporg_field_pill',
        __( 'Pill', 'wporg' ),
        'wporg_field_pill_cb',
        'wporg',
        'wporg_section_developers',
        array(
            'label_for'         => 'wporg_field_pill',
            'class'             => 'wporg_row',
            'wporg_custom_data' => 'custom',
        )
    );
}
add_action( 'admin_init', 'wporg_settings_init' );
 
function wporg_section_developers_callback( $args ) {
    ?>
    <p id="<?php echo esc_attr( $args['id'] ); ?>"><?php esc_html_e( 'Follow the white rabbit.', 'wporg' ); ?></p>
    <?php
}
 
function wporg_field_pill_cb( $args ) {
    wp_editor( '', 'my_custom_editor_id' );
}
 
function wporg_options_page() {
    add_menu_page(
        'WPOrg',
        'WPOrg Options',
        'manage_options',
        'wporg',
        'wporg_options_page_html'
    );
}

add_action( 'admin_menu', 'wporg_options_page' );
  
function wporg_options_page_html() {
    if ( ! current_user_can( 'manage_options' ) ) {
        return;
    }
 
    if ( isset( $_GET['settings-updated'] ) ) {
        add_settings_error( 'wporg_messages', 'wporg_message', __( 'Settings Saved', 'wporg' ), 'updated' );
    }
 
    settings_errors( 'wporg_messages' );
    ?>
    <div class="wrap">
        <h1><?php echo esc_html( get_admin_page_title() ); ?></h1>
        <form action="options.php" method="post">
            <?php
            settings_fields( 'wporg' );
            do_settings_sections( 'wporg' );
            submit_button( 'Save Settings' );
            ?>
        </form>
    </div>
    <?php
}