UnhandledPromiseRejectionWarning: TypeError: Cannot read property 'map' of undefined

Getting error on account creation :-
const defaultPrivateKey = "5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3"; // bob
const signatureProvider = new JsSignatureProvider(['5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3']);
const api = new Api({ rpc, signatureProvider, textDecoder: new TextDecoder(), textEncoder: new TextEncoder() });

const result = await api.transact(
{
account: 'eosio',
name: 'newaccount',
authorization: [{
actor: 'eosio',
permission: 'active',
}],
data: {
creator: 'eosio',
name: 'mynewaccount',
owner: {
threshold: 1,
keys: [{
key: '6FPFZqw5ahYrR9jD96yDbbDNTdKtNqRbze6oTDLntrsANgQKZu',
weight: 1
}],
accounts: [],
waits: []
},
active: {
threshold: 1,
keys: [{
key: '6FPFZqw5ahYrR9jD96yDbbDNTdKtNqRbze6oTDLntrsANgQKZu',
weight: 1
}],
accounts: [],
waits: []
},
},
},
{
blocksBehind: 3,
expireSeconds: 30,
}
);