Derek Sanborn avatar image
Derek Sanborn asked Phong Vu answered

MSG-344 Sending fax to extension numbers is not available

const rcsdk = new SDK({
  server: ringCentral.serverURL,
  clientId: ringCentral.clientId,
  clientSecret: ringCentral.clientSecret

async function getPlatformLoggedIn() {
  const platform = rcsdk.platform()
  await platform.login({ jwt: ringCentral.jwtToken })
  return platform

async function sendFax(input: SendFaxOptions) {
  const formData = new FormData()

  formData.append('attachment', input.attachments[0], { filename: 'correctPDF.pdf', contentType: 'application/pdf' })
  formData.append('to', JSON.stringify(
  formData.append('faxResolution', 'High')
  console.log('Logging in')
  const platform = await getPlatformLoggedIn()
  console.log('Sending Fax')
  const response = await, formData)
  console.log('response: ', JSON.stringify(response, null, 2))

No matter the number I send, it returns the same error message, and judging by the 400 error, I am correctly authenticated, I tried putting invalid credentials and the error happened before I tried to send the fax out.

1 |3000

Up to 8 attachments (including images) can be used with a maximum of 1.0 MiB each and 10.0 MiB total.

1 Answer

Phong Vu avatar image
Phong Vu answered

How do you specify the recipient phone number? It must be in an array. And all the params in the request body must be appended in a JSON string.

Check out the dev guide to learn more how to send faxes.

1 |3000

Up to 8 attachments (including images) can be used with a maximum of 1.0 MiB each and 10.0 MiB total.

Developer sandbox tools

Using the RingCentral Phone for Desktop, you can dial or receive test calls, send and receive test SMS or Fax messages in your sandbox environment.

Download RingCentral Phone for Desktop:

Tip: switch to the "sandbox mode" before logging in the app:

  • On MacOS: press "fn + command + f2" keys
  • On Windows: press "Ctrl + F2" keys