async def _async_service_set_variable_value(hass: HomeAssistant, service: ServiceCall) -> None:
    """Service to call setValue method for Homematic(IP) Local system variable."""
    entry_id = service.data[CONF_ENTRY_ID]
    name = service.data[CONF_NAME]
    value = service.data[CONF_VALUE]

    if control := _async_get_control_unit(hass=hass, entry_id=entry_id):
        await control.central.set_system_variable(legacy_name=name, value=value)
Service to call setValue method for Homematic(IP) Local system variable.
custom_components/homematicip_local/services.py