Is the red slip required at the hospital outpatient checkout an invoice?

The colors of hospital reimbursement documents are different in different provinces. Some are red, some are yellow, and some are white. In addition, the hospital's reimbursement documents are not invoices, because many hospitals are non-profit units. As long as the reimbursement vouchers received by for-profit units are called invoices, the reimbursement documents received by non-profit units are not called invoices. Reimbursement can be made on the coupon with the reimbursement receipt printed on it when you check out the hospital outpatient department.