Unfortunately, if you already have a RAID setup then a SATA DVD burner is very unlikely to work on the same SATA controller. Perhaps your board has a second SATA controller, maybe listed as JMicron?
If it has, you need to connect the DVD burner to that controller and in the BIOS, set it to IDE or emulate IDE mode. Failing you have a second controller, you will need to purchase a PCI SATA addin card.
Let us know which part of the world you’re located in and we’ll try to provide a link to a suitable addin card.