MohammadTanzeelSiddiqui Hello,
There are two model of Oppo A83 exist in their support server,
1. A83 2G = CPH1827
2. A83 3G4G = CPH1729
So, first make sure which one is your version.
Before any flashing procedure, always make identify the firmware version that already in your device at first.
For Oppo device, you can check it via dial *#899#, and go to Software Version(if device is in lockscreen, you can use Emergency Call).
But, because your device is deadboot, so I will upload above firmware in next days for you to try.