We have created a Sandbox Finance which is a mock up bank you can use to test Account Information product.
We suggest you follow Quickstart Guide for integration while below is guidelines on how to use Sandbox Finance in that process.
In those two steps whenever you are required to provide and
SANDBOXFINANCE_SFIN0000 as a value, which will reference using Sandbox Finance for respectively creating an end user agreement and a redirect link for an end user.
When an end user is redirected to Sandbox Finance authentification page, one can provide any input value for user id and code generator fields to continue journey.
When authenitication process by an end user will be finished, you will be able to querry results as for any real connection.