The approach might vary depending on what version of the SDK you are working with.
Maybe you could provide a little more information?
SDK version, what device, softdevice version etc. is useful information to add in your questions.
However, you can take a look at our advertising tutorial, and the chapter about the Scan response data. The tutorial is from one of the older SDK but the approach will be similiar.
Also, the ble_app_uart example adds data to the scan reponse packet, so you can get an idea of how it's done.
Let me know if you have any further questions. Best regards, Joakim.
