private static function _helper_auth_return() {
		if ( empty( $_GET['wc-helper-nonce'] ) || ! wp_verify_nonce( wp_unslash( $_GET['wc-helper-nonce'] ), 'connect' ) ) { // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
			self::log( 'Could not verify nonce in _helper_auth_return' );
			wp_die( 'Something went wrong' );
		}

		// Bail if the user clicked deny.
		if ( ! empty( $_GET['deny'] ) ) {
			/**
			 * Fires when the Helper connection process is denied/cancelled.
			 */
			do_action( 'woocommerce_helper_denied' );
			wp_safe_redirect( admin_url( 'admin.php?page=wc-addons&section=helper' ) );
			die();
		}

		// We do need a request token...
		if ( empty( $_GET['request_token'] ) ) {
			self::log( 'Request token not found in _helper_auth_return' );
			wp_die( 'Something went wrong' );
		}

		// Obtain an access token.
		$request = WC_Helper_API::post(
			'oauth/access_token',
			array(
				'body' => array(
					'request_token' => wp_unslash( $_GET['request_token'] ), // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
					'home_url'      => home_url(),
				),
			)
		);

		$code = wp_remote_retrieve_response_code( $request );

		if ( 200 !== $code ) {
			self::log( sprintf( 'Call to oauth/access_token returned a non-200 response code (%d)', $code ) );
			wp_die( 'Something went wrong' );
		}

		$access_token = json_decode( wp_remote_retrieve_body( $request ), true );
		if ( ! $access_token ) {
			self::log( sprintf( 'Call to oauth/access_token returned an invalid body: %s', wp_remote_retrieve_body( $request ) ) );
			wp_die( 'Something went wrong' );
		}

		WC_Helper_Options::update(
			'auth',
			array(
				'access_token'        => $access_token['access_token'],
				'access_token_secret' => $access_token['access_token_secret'],
				'site_id'             => $access_token['site_id'],
				'user_id'             => get_current_user_id(),
				'updated'             => time(),
			)
		);

		// Obtain the connected user info.
		if ( ! self::_flush_authentication_cache() ) {
			self::log( 'Could not obtain connected user info in _helper_auth_return' );
			WC_Helper_Options::update( 'auth', array() );
			wp_die( 'Something went wrong.' );
		}

		self::_flush_subscriptions_cache();
		self::_flush_updates_cache();

		/**
		 * Fires when the Helper connection process has completed successfully.
		 */
		do_action( 'woocommerce_helper_connected' );

		// Enable tracking when connected.
		if ( class_exists( 'WC_Tracker' ) ) {
			update_option( 'woocommerce_allow_tracking', 'yes' );
			WC_Tracker::send_tracking_data( true );
		}

		// If connecting through in-app purchase, redirects back to WooCommerce.com
		// for product installation.
		if ( ! empty( $_GET['wccom-install-url'] ) ) {
			wp_redirect( wp_unslash( $_GET['wccom-install-url'] ) );
			exit;
		}

		wp_safe_redirect(
			add_query_arg(
				array(
					'page'             => 'wc-addons',
					'section'          => 'helper',
					'wc-helper-status' => 'helper-connected',
				),
				admin_url( 'admin.php' )
			)
		);
		die();
	}