Visma.net have margins only in sales order. You still have access into your sandbox environment with our old email. You can change username (email) in user settings. You will find your user setting from top right corner.
Please have a look in the UI, as Heikki mentioned, you still have access to login to the ERP UI with the old email, not for the forum.
If you can't find the fields in the UI you are looking for, if you could ask your client to provide this, it helps us find the information for you.
If it is not exposed, posting the information here helps the development team and makes it clearer for everyone what you would need exposed via the API.
Necessary fields are ARTran.margin, ARTran.cost, ARTran.TranCost and ARtran.UnitCost.
Relevant thing here is to GET margin and cost information to external reporting systems. OneStopReporting for example is useless for invoice reporting without these and invoice reporting is the key for most reporting.
These fields are not visible in the UI. There is an other Idea to get them visible in the UI too. Anyway these fields are in the database and they can be used with generic inquiries and report designer for example.