Not Able to initalize bundlr for etherum

Question

const privateKey = user_wallet.private_key;
const bundlr = new Bundlr(arweaveUrl, "Ethereum", privateKey );
await bundlr.ready();

Im not able to initalize Bundlr for etherum.

Giving me the following error

{
    "message": "Invalid typed array length: 0xPRIVATEKEY"
}