Hasura event trigger to update value before insert

[ghost]

Hi Team, I have met a case, when I create an Event trigger to call to serverless function (Openfaas), I want to change value of some fields before insert into DB. But when I try to update, nothing happen, the console log the new value but data inserted have no change, please help me on it, below is code example

event.body.event.data.new = {
    ...event.body.event.data.new,
    password: 'newpass'
}
console.log('eventevent', event)