Show customizer panel just on Portfolio archive page

portfolio-customizer.php

<?php

function prefix_customizer_register( $wp_customize ) {

	$wp_customize->add_panel( 'panel_id', array(
	    'priority' => 10,
	    'capability' => 'edit_theme_options',
	    'theme_supports' => '',
	    'title' => __( 'Example Panel', 'textdomain' ),
	    'description' => __( 'Description of what this panel does.', 'textdomain' ),
	    'active_callback' => 'callback_portfolio',
	) );

	function callback_portfolio(){ 
		return is_post_type_archive( 'portfolio' );;
	}

	$wp_customize->add_section( 'section_id', array(
	    'priority' => 10,
	    'capability' => 'edit_theme_options',
	    'theme_supports' => '',
	    'title' => __( 'Example Section', 'textdomain' ),
	    'description' => '',
	    'panel' => 'panel_id',
	) );

	$wp_customize->add_setting( 'textarea_field_id', array(
	'default' => '',
	'type' => 'theme_mod',
	'capability' => 'edit_theme_options',
	'transport' => '',
	'sanitize_callback' => 'esc_textarea',
	) );

	$wp_customize->add_control( 'textarea_field_id', array(
	    'type' => 'textarea',
	    'priority' => 10,
	    'section' => 'section_id',
	    'label' => __( 'Textarea Field', 'textdomain' ),
	    'description' => '',
	) );

}
add_action( 'customize_register', 'prefix_customizer_register' );