I have successfully install the miracl to my linux OS,but I cannot use some functionlity definede in the "miracl.h" fine

[vegetablebirdjwx]

this is my code to implement a founctionlity to caculate hash value of any input
#include <stdio.h>
#include "miracl.h"
void calculate_sha256_hash(const char* input, char* output) {
sha256 sh;
int i;
char digest[32];

shs256_init(&sh);
for (i = 0; input[i] != 0; i++) {
    shs256_process(&sh, input[i]);
}
shs256_hash(&sh, digest);

for (i = 0; i < 32; i++) {
    printf(output + (i * 2), "%02x", digest[i]);
}

}
in the miracl.h file these three functionlity have been defined as followed
extern void shs_init(sha *);
extern void shs_process(sha *,int);
extern void shs_hash(sha *,char *);

so what should I do to use these functionlity