How to Trigger TIM2 via TIM3?

Hi.

I'm reading Incremental Optic encoder with Timer3. The counter value is 4095 when the encoder rotates one turn. My goal is to produce pulses from 0-25ms through another timer when the Encoder turns half a turn.

In order to do this, I am trying to trigger Timer2 via Timer3. But I couldn't run

This is Encoder Timer Settings

void Encoder_Init(void)
{
 TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
	TIM_OCInitTypeDef TIM_OCInitStructure;
	GPIO_InitTypeDef GPIO_InitStructure;
	
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);
 
	// Step 1: Initialize GPIO as input for rotary encoder
	//PA6 (TIM3_CH1) (encoder pin A), PA7 (TIM3_CH2) (encoder pin B)
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
	TIM_TimeBaseStructure.TIM_Prescaler = 0;
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up | TIM_CounterMode_Down;
	TIM_TimeBaseStructure.TIM_Period = 4095;
	TIM_TimeBaseStructure.TIM_ClockDivision = 0;
	TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
	
 /* Output Compare Active Mode configuration: Channel1 */
 TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
 TIM_OCInitStructure.TIM_Pulse = 1000;
 TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
 TIM_OC1Init(TIM3, &TIM_OCInitStructure);
	
	TIM_SetCounter(TIM3,0);
 
	TIM_EncoderInterfaceConfig(TIM3, TIM_EncoderMode_TI12, TIM_ICPolarity_Rising, TIM_ICPolarity_Rising);
	
	TIM_SelectOutputTrigger(TIM3,TIM_TRGOSource_OC1Ref);
	
	TIM_Cmd(TIM3, ENABLE);
	
}

Slave Timer settings

void SlaveTimerInit(void)
{
 TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
 TIM_OCInitTypeDef TIM_OCInitStructure;
 GPIO_InitTypeDef GPIO_InitStruct;
	
 // Enable clock
 RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
	
 GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0;
 GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
 GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP;
 GPIO_Init(GPIOA, &GPIO_InitStruct);
	
	 // Time Base configuration
	TIM_TimeBaseStructure.TIM_Prescaler = 72-1;
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
	TIM_TimeBaseStructure.TIM_ClockDivision = 0;
	TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
	
 /* TIM2 PWM2 Mode configuration: Channel1 */
 TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
 TIM_OCInitStructure.TIM_Pulse = 20000; //20ms
 TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
 
 TIM_OC1Init(TIM2, &TIM_OCInitStructure);
	
 /* One Pulse Mode selection */
 TIM_SelectOnePulseMode(TIM2, TIM_OPMode_Single);
	
 /* Input Trigger selection */
 TIM_SelectInputTrigger(TIM2, TIM_TS_ITR0);
 
 /* Slave Mode selection: Trigger Mode */
 TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Trigger);
	
}

Where am I making mistakes? Thanks. How to do it?