SendPaymentV2 not recognising destCustomRecord for keysend

[danarchos]

Trying to send a keysend payment with sendPaymentV2 as below.

    const response = await rpc.sendPaymentV2({
      dest: Buffer.from(pubKey, "hex"),
      amt: 210,
      allowSelfPayment: true,
      timeoutSeconds: 30,
      paymentHash: preimage.toString("base64"),
      destCustomRecords: [[5482373484, Buffer.from(preimage)]],
    });

I am using the key 5482373484 but getting back an error:

no custom records with types below 65536 allowed