From What is the iBeacon Bluetooth Profile I understood the format of iBeacon. In Project #008: GAP Broadcaster it is mentioned that iBeacon is based on GAP Broadcaster approach. However, PSoC Creator doesn't allow me to customize advertisement packet to make iBeacon based on GAP Broadcaster template. How can I do it?
You can create a new adv type packet and use the API CyBle_GapUpdateAdvData() to update advertisement data. Try the project at: https://github.com/cypresssemiconductorco/PSoC-4-BLE/tree/master/100_Projects_in_100_Days/Day009_Dynamic_Broadcaster