I'm guessing that as this is ICB Level 2 computerised and there is only one exam then you will take this after completing the three books. Are you doing this with a training provider? If so, they should have told you.
The computerised exams are usually home-based assessments, to be completed within a given time.
I have completed the Level 1 Book Keeping course. I have started the Basic level workbook for this computerised course, and coming towards the end of it. I was wondering whether or not to contact my provider (Training Link) to ask them if it is ok if I carry on to the intermediate book or do I need to be assessed before carrying on?