Click the 'Missed detentions' tab. You will see a list of detentions that have been missed.
To create a new time, date and location for the detention click on a pupil tile. This will bring up the detention sidebar and you can schedule it with the details you want.
To schedule multiple new detentions for the same time, tick the 'Award/edit multiple pupils' checkbox at the top of the detentions menu.
You can then select multiple pupil tiles by clicking on them and then click 'award/edit button to modify the detention.
Then simply schedule in the details you want.
You can view the pupils in either a list view, block view or by exporting to excel using the three buttons on the right hand side.
You can filter missed detentions by a number of criteria, which can be accessed at the top of the detentions menu.