No, you're using the Oanda API directly.

Start over....

* Close Zorro and open it again.
* Set User to your v20 demo account (it must look like "123-456-78999-007")
* Set Account to Demo (this is a demo account, yes?)
* Set Plugin to Oanda V20
* Clear your password field completely.
* Reset your API key on the Oanda website.
* Copy the new key directly from the Oanda website.
* Paste the new key into the password field.

Now try out your script.