File system task is used to manipulate files similar to how you might with Windows Explorer. In this instance that is not going to help you move the file to an external HTTPS site.

I would wait and see the type of access the username and password are going to offer. If the upload method provided by the vendor is simply a form entry it will be difficult to automate that with SSIS.

If the vendor also offers secure FTP you could use SSIS to do this but would require a third party add-on or script since SSIS FTP task does not support security FTP. The other option might be sending this to a web service through an XML format, there is a task in SSIS for doing this.