javascript – Bitcore-Lib generate OmniLayer Transactions

I am trying to create OmniLayer Transaction with Bitcore-Lib , but the OP_RETURN format using Bitcore-Lib Transaction.addData() like:

const simple_send = (
        "6f6d6e69", // omni 4bytes
        "0000", //Version: 0 : 2bytes
        "0000", // Type : 0 : 2bytes
        property_id.toString(16).padStart(8,'0') , // PropertyID : 4bytes
        (property_amount*100000000).toString(16).padStart(16,'0') // Amount: 8Bytes
    ).join('')

and addthis data in the transaction as:

const tx = new Transaction()
            .from(utxos)
            .addData(simple_send);

But it generates transaction data (in Explorer) as (Using Property_id = 1 and amount as 1):

OP_RETURN (6f6d6e69000000000000000000010000000005f5e100)

In raw transaction it comes out as :

OP_RETURN 3666366436653639303030303030303030303030303030303030303430303030303030303035663565313030

Instead of expected:

OP_RETURN 6f6d6e6900000000000000040000000005f5e100

I believe the encoding is not proper but not sure how to get it correct , as i have tried few things already to get the correct OP_RETURN