I’m trying to create BLE GATT services on my Raspberry Pi 4 using C++. Have searched for a while but wasn’t able to find useful hints/examples.

More details:
I’m able to create GATT services and characteristics using commands:

#bluetoothctl
[bluetoothctl] menu gatt
[bluetoothctl] register-service 0xFFFF #
[bluetoothctl] register-characteristic 0xAAAA read,write #
[bluetoothctl] register-application #

and I want to achieve the same using C++ codes.

I have found the definition for void RegisterApplication(object application, dict options) in https://github.com/Vudentz/BlueZ/blob/master/doc/gatt-api.txt, but it doesn’t provide many details. My question is:
For this RegisterApplication function, what should I put for the ‘object application’ and ‘dic options’? Is there any example in the format of

g_dbus_proxy_call(
        Proxy,         
        "RegisterApplication",       
        Params,                       
        G_DBUS_CALL_FLAGS_NONE,      
        -1,                  
        NULL,
                NULL,
                NULL);

showing how the “params” should be constructed for my service and characteristic (registered using commands) above?