Call function with parameter by Timer API

On RUI3 Timer API, How do I call function by Timer API with an Integer value as a parameter?

I am using parameters in my RUI3-Signal-Meter-P2P-LPWAN

Start timer with parameter:

	display_reason = 1;
	api.system.timer.start(RAK_TIMER_1, 250, &display_reason);

Timer callback with parameter usage:

void handle_display(void *reason)
{
	// Get the wakeup reason
	uint8_t *disp_reason = (uint8_t *)reason;

	// Check if we have a reason
	if (disp_reason == NULL)
	{
		Serial.println("Bug in code!");
	}
	else if (disp_reason[0] == 1)
	{
		// RX event display
	}
	else if (disp_reason[0] == 2)
	{
	}
	else if (disp_reason[0] == 3)
	{
	}
	else if (disp_reason[0] == 5)
	{
	}
}

Thank you for your support.

I can start Timer API with parameter as you show me, but I wonder if it posible to start Timer API with a local variable as parameter? If yes, how can I do that?
I’ve try with this code, but it not work.

// uint8_t testValue = 1;

void testing(void *ch){
    uint8_t *channel = (uint8_t*)ch;
    if (channel[0] == NULL)
    {   
        Serial.println("Testing");
    } else {
        Serial.printf("Testing with parameter: %d\r\n", channel[0]);
    } 
}

void setup()
{
    Serial.begin(115200);
    Serial.println("Starting...");
    api.system.timer.create(RAK_TIMER_0,(RAK_TIMER_HANDLER)testing, RAK_TIMER_PERIODIC);
    uint8_t testValue = 1;
    testing(&testValue);
    api.system.timer.start(RAK_TIMER_0, 1000, &testValue);
}

void loop()
{
    api.system.sleep.all();
}

No it is not possible.
As you can see the parameter is given as a pointer to the parameter.
If you define the parameter local, it will be on the stack and destroyed when the function returns.

Many thanks for the clear explanation.