The linux command:

curl -F data=@data.txt -F templateName=samples/WelcomeTemplate.docx -F outputName=myWelcome.pdf -F accessKey=XXX -o myWelcome.pdf https://dws2.docmosis.com/services/rs/render

will call the cloud service to render the template samples/WelcomeTemplate.docx to create file myWelcome.pdf. 

The access key above is XXX which you should replace with your access key

You will also need to creqate a data.txt file that contains the data in JSON format, that should look like this:
 
{
 "title":"Welcome to Docmosis via cURL",
 "messages":
 [{"msg":"This cloud experience is better than I thought."},
  {"msg":"The sun is shining."},
  {"msg":"Right, now back to work."}]
}