Trouble with: setAdvertising heart_rate

I have been trying to advertise as various things from the Puck, but the only things I can get to show up as being described properly in nRF are the examples, Temperature and Battery Life. I can't get blood pressure or environmental sensing to show up. I think you have to provide a byte array as data which has some required parameters for some services, but I don't know how to tell what data it needs or how to give it to it! The eddystone example works too, and that has a load of bytes in an array.

NRF.setAdvertising([0x03,  // Length of Service List
  0x03,  // Param: Service List
  0xAA, 0xFE,  // Eddystone ID
  0x13,  // Length of Service Data
  0x16,  // Service Data
  0xAA, 0xFE, // Eddystone ID
  0x10,  // Frame type: URL
  0xF8, // Power
  0x03, // https://
  'g','o','o','.','g','l','/','B','3','J','0','O','c'],
    {interval:100});

I don't really understand the gatt spec website either.