1. First, you'll need to put your number list into CSV format.
If your list is currently an excel spreadsheet, you can convert it by clicking File > Save As, then changing the type to "Comma separated values (CSV)"
Plain text list or other formats:
If your list is in word, or another format, you will need to copy and paste the numbers into a plain text file.
The text file should consist of one fax number per line.
2. Upload the CSV file to the Fax webApp under Outbound > New Bulk Message