I want to create an invoice with some metadata so that I can identify the invoice type in my app. However, it seems that the CreateInvoiceRequest() method ignores the "metadata" field. When I bypass it (by directly passing the data into the createInvoice() method), it still behaves the same.

Here's my code:

 try {
            $resp = array();
            $invoiceRequest = new CreateInvoiceRequest($validated);
            $invoiceCreated1 = $apiInstance->createInvoice($invoiceRequest);
            $invoiceCreated2 = $apiInstance->createInvoice($validated);

            dd($invoiceCreated1,$invoiceCreated2); // both return the same
}

For the record, the documentation for this package also seems to ignore the metadata field. But why? According to the API documentation here, it clearly states that we can use metadata.