Error in class-dibs-post-checkout.php on line 131 and 133

When I cancel an order I get this error:

[09-Jun-2021 21:39:11 UTC] PHP Fatal error:  Uncaught TypeError: array_key_exists(): Argument #2 ($array) must be of type array, stdClass given in /public_html/wp-content/plugins/dibs-easy-for-woocommerce/classes/class-dibs-post-checkout.php:131
Stack trace:
#0 /public_html/wp-includes/class-wp-hook.php(294): DIBS_Post_Checkout->dibs_order_canceled()
#1 /public_html/wp-includes/class-wp-hook.php(316): WP_Hook->apply_filters()`

There is two errors, on line 131 and 131. Here are the entire code-chunk:

$request = new DIBS_Requests_Cancel_Order( $order_id );
$request = json_decode( $request->request() ); // COMMENT: Returns an object!!

$wc_order = wc_get_order( $order_id );

if ( null === $request ) {
	$wc_order->add_order_note( sprintf( __( 'Order has been canceled in Nets', 'dibs-easy-for-woocommerce' ) ) );
} else {
	if ( array_key_exists( 'errors', $request ) ) { // COMMENT: should be isset instead of array_key_exists. It's an object, not an array.
		$message = wp_json_encode( $request->errors );
	} elseif ( array_key_exists( 'message', $request ) ) { // COMMENT: should be isset instead of array_key_exists. It's an object, not an array.
		$message = wp_json_encode( $request->message );
	} else {
		$message = wp_json_encode( $request );
	}
	/* Translators: Nets message. */
	$wc_order->add_order_note( sprintf( __( 'There was a problem canceling the order in Nets: %s', 'dibs-easy-for-woocommerce' ), $message ) );
}

I’ve added comments above.

In short, then array_key_exists( 'message', $request ) should be replaced with isset( $request->message ).