Uploading firmware to multiple device in campain mode

Hello, I have two identical devices (F429ZI) and I am following the Pellion getting started tutorial on how to over the air upgrade these devices. For one device, I use the mbed-os-example-pelion code and after creating the connect certificate I apply it to the code so the file mbed_cloud_dev_credentials.c with the bootstrapping credentials is changed. After following all steps the firmware upgrade process is succeed. However, when I add the second device I am not sure what I have to change in the mbed-os-example-pelion code in order to make this device works too. If a compile and flash (via usb) the same firmware how this device will be different and after this step how Can I use the same binary for 2 device if the credentials are different? (I assume that the credentials are saved into the binary and in the second device the mbed_cloud_dev_credenials.c would be different (I may be wrong)). I would appreciate if somebody would explain to me the procedure.