Attaching Multiple Documents for Fax

Yes, you can send multiple attachments. Just make sure the total of all attachments size must not exceed the max size of 50MB. See this code sample using the RingCentral JS SDK.

async function send_fax() {
  try{
    var endpoint = "/restapi/v1.0/account/~/extension/~/fax"
    var FormData = require('form-data');
    formData = new FormData();
    var body = {
      to: [{'phoneNumber': "RECIPIENT_NUMBER", 'name': "Recipient name" }],
      faxResolution: "High"
      coverPageText: "This is a demo Fax page from Node JS
 
Recipient company
 
Sender name
 
Fax number
 
Subject is subject
 
Comments/Notes"
    }

    formData.append('json', new Buffer.from(JSON.stringify(body)), {
        filename: 'text.json',
        contentType: 'application/json'
        });

    formData.append('attachment', require('fs').createReadStream('first_file.jpg'));
    formData.append('attachment', require('fs').createReadStream('second_file.png'));

    var resp = await platform.post(endpoint, formData)
    var jsonObj = await resp.json()
    console.log("FAX sent. Current status: " + jsonObj.messageStatus + "/" + jsonObj.id)
  }catch(e){
    console.log(e.messsage)
  }
}

See the dev guide documentation for more details