Question: how to create an account_update transaction?

[combustpizza]

I don't quite understand how to create an account_update transaction, I tried adding the operation like so:

    const tx = new TransactionBuilder();

    tx.add_type_operation('account_update', {
        fee: {
            amount: 0, 
            asset_id: '1.3.1'
        },
        account: user.id,
        owner: {
            weight_threshold: 1,
            account_auths: [],
            key_auths: [ PublicKey.fromPublicKeyString('GXC76CWcEHaLnyWbcWmEiMRnMn9LfcTQQ5sDypx29Ei4Yp3BtxgzV'), 1 ],
            address_auths: []
        },
        active: {
            weight_threshold: 1,
            account_auths: [],
            key_auths: [ PublicKey.fromPublicKeyString('GXC76CWcEHaLnyWbcWmEiMRnMn9LfcTQQ5sDypx29Ei4Yp3BtxgzV'), 1 ],
            address_auths: []
        },
        new_options: {
            memo_key: PublicKey.fromPublicKeyString('GXC76CWcEHaLnyWbcWmEiMRnMn9LfcTQQ5sDypx29Ei4Yp3BtxgzV'),
            voting_account: '1.2.5',
            num_witness: 0,
            num_committee: 0,
            votes: [],
            extensions: []
        },
        extensions: []
    });

And this results in:

account_update.owner	 cause: authority.key_auths	 cause: value required  undefined 
 stack: Error: value required  undefined
    at Object.required (/home/user/NodeJS/test/node_modules/gxbjs/dist/serializer/src/SerializerValidation.js:39:19)

I also tried to pass the keys as strings, but would get this error:

Expecting key to begin with GXC, instead got G.

I'm not sure what I'm doing wrong here...

[xzshinan]

@combustpizza try it like this:
key_auths: [[ 'GXC76CWcEHaLnyWbcWmEiMRnMn9LfcTQQ5sDypx29Ei4Yp3BtxgzV', 1 ]],