Add attachments into a campaign message. Only applicable for campaign message of type email

curl --request POST \
     --url https://api.campaign.episerver.net/rest/{clientId}/smartcampaigns/{campaignId}/messages/{mailingId}/attachments \
     --header 'accept: application/json'

var myHeaders = new Headers();
myHeaders.append("accept", "application/json");
myHeaders.append("content-type", "application/x-www-form-urlencoded");

var requestOptions = {
   method: 'POST',
   headers: myHeaders,
   redirect: 'follow'
};

fetch("https://api.campaign.episerver.net/rest/{clientId}/smartcampaigns/{campaignId}/messages/{mailingId}/attachments", requestOptions)
   .then(response => response.text())
   .then(result => console.log(result))
   .catch(error => console.log('error', error));

require "uri"
require "net/http"

url = URI("https://api.campaign.episerver.net/rest/{clientId}/smartcampaigns/{campaignId}/messages/{mailingId}/attachments")

https = Net::HTTP.new(url.host, url.port)
https.use_ssl = true

request = Net::HTTP::Post.new(url)
request["accept"] = "application/json"
request["content-type"] = "application/x-www-form-urlencoded"

response = https.request(request)
puts response.read_body

import requests

url = "https://api.campaign.episerver.net/rest/{clientId}/smartcampaigns/{campaignId}/messages/{mailingId}/attachments"

payload = {}
headers = {
   'accept': 'application/json',
   'content-type': 'application/x-www-form-urlencoded'
}

response = requests.request("POST", url, headers=headers, data=payload)

print(response.text)

// The attachments were successfully added into campaign message.

// The "attachmentIds" parameter is either empty or invalid, or the campaign mailing is of type FAX.

// The campaign mailing was not found.

// The campaign message is not of type EMAIL.