Under normal circumstances, the hospital will issue a certificate. If only one receipt is issued, you should ask whether there is a temporary shortage of invoices or whether to stop issuing invoices that month. Let you take the payment voucher (receipt) first, and then change the invoice when you can make an invoice.
This is also the case. I suggest going to the office to find out, because the receipt can't be recorded, so it can't be reimbursed.