I believe the issue here is that that first, at the broker's web site, you have to expressly allow "3rd parties" to access your data. Poke around at the broker's web site to see if you can find this setting or, even easier, just call the broker and ask where this permission is located. I know that at Schwab's site there's a "Security center" and within that Security center there's a section called "Third-Party Access to Account Information."