This endpoint allows you to send a list of messages through a CSV file.
Receives the format to generate the message to send in JSON format.
This format must be composed with the template data to be used, with special emphasis on the namespace,
the template name and the variables used in the template components.
The CSV, for each destination, must have information about the variables defined in the template.
The header of the file must correspond to the JSON sent that corresponds to a given template.