Pass Express Backend error into front end catch block [duplicate]

In the below code, a 404 status is sent up to the front end causing the res.ok property to be false. Is there a way to have access to this message from the backend in the front end if statement where the res.ok value is checked?

app.post('/recover_password', (req, res) => {
  const customer_has_account = true

  if (!customer_has_account) {
    return res.status(404).json('no account found with that email')
  }
})

fetch('/recover_password', {
  method: 'POST',
  body: /* ... */
})
  .then(res => {
    if (!res.ok) {
      throw new Error(/* can error be passed in here somehow? */)
    }
    return res.json()
  })
  .then(data => console.log(data))
  .catch(err => {
    console.log(err)
  })

I suppose this would also work but I am wondering if there is a specific way to do this as shown above

app.post('/recover_password', (req, res) => {
  const customer_has_account = true

  if (!customer_has_account) {
    return res.status(404).json({ error: 'no account with that email found '})
  }
})

fetch('/recover_password', {
  method: 'POST',
  body: /* ... */
})
  .then(res => res.json())
  .then(data => {
    if (data.error) throw new Error(data.error)
  })
  .catch(err => console.log(err))

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