This code works very well - you are just doing something wrong. (I know - I am the developer of this code, and I work with it every day, doing exactly what you are looking for).
With that said, since you did not post any error codes or messages, no one can help you.
Post some error messages or code.
Other features:
But I can not get any data.
Why not? What specific error do you get? What does your code look like? What types of data are you trying to get?
I'm just trying to automate some of the processes for my company with our quick books - online store integration.
If everything you build is a one-time / user integration for your company, then you started from the wrong path. Intuit Anywhere (OAuth material) is for SaaS applications only (see Frequently Asked Questions here: https://ipp.developer.intuit.com/0010_Intuit_Partner_Platform/0025_Intuit_Anywhere/0080_FAQ , in particular: "I want to integrate my regular (non-SaaS, single-user) solution with Intuit Anywhere. Can I do this? ").
You should use qbXML instead. Download STABLE: QuickBooks PHP DevKit
And look at docs / example_online_edition.php
The rest of the Intuit documentation for qbXML (not Intuit Anywhere) is here: http://developer.intuit.com/qbsdk-current/common/newosr/index.html
Basically, I just don't understand what to do to get a list of PO addresses from online books.
Unfortunately, you will find that sample purchase orders are not supported by EIFER from the two APIs available for QuickBooks Online.
All Intuit QuickBooks Online APIs have always been incomplete. Neither supports purchase orders. If you really need purchase order support, switch to QuickBooks for Windows instead.
If you need additional help / problems, MAKE SURE that you publish your code and any error messages so that we can help you in the future.