MSP430FR5994: UART - Working code but nothing is printed on terminal

//UART test 1 - Polling

#include  <msp430.h> 

#define RXD        BIT1 
#define TXD        BIT0 
#define BUTTON    BIT5

void UART_TX(char * tx_data);            // Function Prototype for TX

void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;         // Stop Watch dog timer

  // Disable the GPIO power-on default high-impedance mode to activate previously configured port settings
  PM5CTL0 &= ~LOCKLPM5;

  // Clock setup
  CSCTL0_H = CSKEY >> 8;                                                                      // Unlock CS registers
  CSCTL1 = DCOFSEL_3 | DCORSEL;                                                       //Set DCO to 8MHz
  CSCTL2 = SELA__VLOCLK | SELS__DCOCLK | SELM__DCOCLK;     // Set ACLK = VLOCLK; MCLK = SMCLK = DCO
  CSCTL3 = DIVA__1 | DIVS__1 | DIVM__1;                                              // Set all dividers to 1

  // Lock CS registers
  CSCTL0_H = 0;

  P5DIR &=~BUTTON;                          // Ensure button is input 

  P1OUT &= ~BIT0;                               // Clear P1.0 output latch
  P1DIR |= BIT0;                                    // For LED

  P5OUT |=  BUTTON;                         // Enables pullup resistor on button
  P5REN |=  BUTTON;

  P6SEL1 &= ~(BIT0 | BIT1);
  P6SEL0 |= (BIT0 | BIT1);                     // USCI_A3 UART operation

  UCA3CTLW0 = UCSWRST;                             // Put eUSCI in reset
  UCA3CTLW0 |= UCSSEL__SMCLK;               // CLK = SMCLK
  // Baud Rate calculation
  // 8000000/(16*9600) = 52.083
  // Fractional portion = 0.083
  // User's Guide Table 21-4: UCBRSx = 0x04
  // UCBRFx = int ( (52.083-52)*16) = 1
  UCA3BRW = 52;                                                           // 8000000/16/9600
  UCA3MCTLW |= UCOS16 | UCBRF_1 | 0x0400;       //
  UCA3CTLW0 &= ~UCSWRST;                                  // Initialize eUSCI

  while(1)                          // polling
  {
      if(!((P5IN & BUTTON)==BUTTON)) // Was button pressed?
      {
          P1OUT ^= BIT0;                             // to ensure code is working - red led will be toggled as button is pressed
          UART_TX("Hello World! \r\n");      // If yes, Transmit message
          __delay_cycles(2000000);           //not to Debounce button so signal is not sent multiple times
      }
  }

}

void UART_TX(char * tx_data)                               // Define a function which accepts a character pointer to an array
{
    unsigned int i=0;
    while(tx_data[i])                                                   // Increment through array, look for null pointer (0) at end of string
    { 
        while ((UCA3STATW & UCBUSY));                 // Wait if line TX/RX module is busy with data
        UCA3TXBUF = tx_data[i];                                // Send out element i of tx_data array on UART bus
        i++;                                                                   // Increment variable for array address
    }
}

//UART test 2 - interrupts
#include<msp430.h>

//prototypes
void UARTInit(void);
void TXData(unsigned char c);

void main(void){
     WDTCTL = WDTPW + WDTHOLD;// watchdog timer kapali
   
     // Clock setup
     CSCTL0_H = CSKEY >> 8;                                                                     // Unlock CS registers
     //CSCTL1 = DCOFSEL_0;                                                                       // Set DCO to 1MHz
     CSCTL1 = DCOFSEL_3 | DCORSEL;                                                    //Set DCO to 8MHz
     CSCTL2 = SELA__VLOCLK | SELS__DCOCLK | SELM__DCOCLK;   // Set ACLK = VLOCLK; MCLK = SMCLK = DCO
     CSCTL3 = DIVA__1 | DIVS__1 | DIVM__1;                                             // Set all dividers to 1

     // Lock CS registers 
     CSCTL0_H = 0;

     // Disable the GPIO power-on default high-impedance mode to activate previously configured port settings
     PM5CTL0 &= ~LOCKLPM5;

      P1OUT &= ~BIT0;                           // Clear P1.0 output latch
      P1DIR |= BIT0;                                // For LED
 
      P5DIR &= ~BIT5;                      //P5.5 input
      P5OUT |=  BIT5;                   
      P5REN |=  BIT5;                      // Enables pullup resistor on button
      P5IE |= BIT5;                           //  interrupt enabled
      P5IES |= BIT5;                         //  Hi/lo edge
      P5IFG &= ~BIT5;                     // IFG cleared
 
    UARTInit();

    __bis_SR_register(GIE);

}


void UARTInit(void){
    P6SEL1 &= ~(BIT0 | BIT1);
    P6SEL0 |= (BIT0 | BIT1);                                        // USCI_A3 UART operation

    UCA3CTLW0 = UCSWRST;                                   // Put eUSCI in reset
    UCA3CTLW0 |= UCSSEL__SMCLK;                    // CLK = SMCLK
    // Baud Rate calculation
    // 8000000/(16*9600) = 52.083
    // Fractional portion = 0.083
    // User's Guide Table 21-4: UCBRSx = 0x04
    // UCBRFx = int ( (52.083-52)*16) = 1
    UCA3BRW = 52;                                                       // 8000000/16/9600
    UCA3MCTLW |= UCOS16 | UCBRF_1 | 0x0400; 
    UCA3CTLW0 &= ~UCSWRST;                                 // Initialize eUSCI

    UCA3IE |= UCRXIE; 
}

void TXData(unsigned char c){
    while(!(UCA3IFG & UCTXIFG));
    UCA3TXBUF = c; 
}

// Port 1 interrupt service routine/**/
   #pragma vector=PORT5_VECTOR
   __interrupt void Port_5(void)
   {
       P1OUT ^= BIT0;
       TXData('M');
       __delay_cycles(400000);                prevent multiple send

      P5IFG &= ~BIT5;                         
   }