AES_GCM with Luna: TypeError: Argument 1 has wrong type. Property 'type' should be a Number

[cveto]

I am trying to use pkcs11js with Thales Luna HSM. Works fine with AES_CBC, but getting it to work with AES_GCM is giving me some trouble.

I think the issue could be with the IV parameter, but I am not sure.
With Luna, IV can not be provided to the HSM, but the HSM generates it. in C, I can get it working by just setting pointer of IV in CK_GCM_PARAMS to NULL
params.pIv = NULL;

The error I get which is triggered just after C_EcryptInit is:

TypeError: Argument 1 has wrong type. Property 'type' should be a Number
    at PKCS11.C_EncryptInit (/home/e143810/nodejs/node_modules/pkcs11js/index.js:77:22)
    at Object.<anonymous> (/home/e143810/nodejs/f_encrypt_AES128GCM.js:85:12)

The code I am using is quite basic:

 /**
    * Your app code here
    */
    var template = [
        { type: pkcs11js.CKA_CLASS, value: pkcs11js.CKO_SECRET_KEY },
        { type: pkcs11js.CKA_TOKEN, value: false },
        { type: pkcs11js.CKA_LABEL, value: "My AES Key2" },
        { type: pkcs11js.CKA_VALUE_LEN, value: 256 / 8 },
        { type: pkcs11js.CKA_ENCRYPT, value: true },
        { type: pkcs11js.CKA_DECRYPT, value: true },
    ];
    var secretKey = pkcs11.C_GenerateKey(session, { mechanism: pkcs11js.CKM_AES_KEY_GEN }, template);
    console.log("key handle:",secretKey.toJSON());

    // Generate AES GCM parameters
    // Generate random IV and setup IV params
    //var iv = pkcs11.C_GenerateRandom(session, new Buffer.alloc(12));
    var iv = new Buffer.alloc(32);
    // Generate Additional Authentication Data(AAD) bytes
    var aad = new Buffer.from("AAAD");
    // Generate iv bits size
    var ivBits = 12*8;//96
    // Generate tag bits size
    var tagBits = 128;
    var type = 3;//MechParams.AesGCM;
    console.log("MechParams.AesGCM=",3);//MechParams.AesGCM);
    var gcm_params = {
      iv,
      ivBits: iv.length * 8,
      aad: aad,
      aadBits: aad.length * 8,
      tagBits,
    };

    pkcs11.C_EncryptInit(
        session,
        {
            mechanism: pkcs11js.CKM_AES_GCM,
            parameter: gcm_params
        },
        secretKey
    );