OpenSSL BIGNUM issue, when migrating from 1.0.2 to 1.1.1

Question

I am facing OpenSSL BIGNUM issue when migrating from 1.0.2 to 1.1.1 version.

I included openssl/bn.h, but the compiler says :

"incomplete type is not allowed static const BIGNUM pubmod"

Here is the code:

static const BN_ULONG pubkey[] = { 0x64F5FBD3, 0xA308B0FE};

static const BIGNUM pubmod = { (BN_ULONG *) pubkey,
    sizeof(pubkey)/sizeof(BN_ULONG),
    sizeof(pubkey)/sizeof(BN_ULONG),
    0,
    BN_FLG_STATIC_DATA
};

I also tried:

 BIGNUM *pubmod = BN_new();

How can I do it in 1.1.1? Do I need to go with functions with BN_hex2bn?

How should I add the pubkey to BIGNUM variable?

Any suggestions, please?