Running make command throws issue error: ‘crypto_sign_SEEDBYTES’ was not declared in this scope

Question

I am running the make command as suggested by the documentation, but i am getting below error:

./include/mega/crypto/sodium.h:38:40: error: ‘crypto_sign_SEEDBYTES’ was not declared in this scope
   38 |     static const int SEED_KEY_LENGTH = crypto_sign_SEEDBYTES;

Below is code snippet from sodium.h

#ifndef SODIUM_H
#define SODIUM_H 1

#include </include/mega/crypto/sodium.h>
#include <vector>


namespace mega {

class PrnGen;

/**
 * @brief Asymmetric cryptographic signature using EdDSA with Edwards 25519.
 */
class MEGA_API EdDSA
{
public:
    static const int SEED_KEY_LENGTH = crypto_sign_SEEDBYTES;

I am not sure why, I am getting this issue. Where should I define crypto_sign_SEEDBYTES. Should it be a part of the library which must be installed?