C lang int to string

#include <stdio.h>

#define NUMBER_OF_DIGITS 16   /* space for NUMBER_OF_DIGITS + '\0' */

void uitoa(unsigned int value, char* string, int radix)
{
unsigned char index, i;

  index = NUMBER_OF_DIGITS;
  i = 0;

  do {
    string[--index] = '0' + (value % radix);
    if ( string[index] > '9') string[index] += 'A' - ':';   /* continue with A, B,.. */
    value /= radix;
  } while (value != 0);

  do {
    string[i++] = string[index++];
  } while ( index < NUMBER_OF_DIGITS );

  string[i] = 0; /* string terminator */
}

void itoa(int value, char* string, int radix)
{
  if (value < 0 && radix == 10) {
    *string++ = '-';
    uitoa(-value, string, radix);
  }
  else {
    uitoa(value, string, radix);
  }
}


int main()
{
    char TxBuffer1[5] ="1 123";
    // printf(TxBuffer1);
    char* command;
    
    for(int i = 0; i < sizeof(TxBuffer1); i++)
    {          
itoa (i, command, 10);
printf(command);
        // if (i == 0) {
        //     printf(TxBuffer1[i+1]);
        //     command = TxBuffer1[i+1];

        // }
    }
    
    // printf(command);

    return 0;
}