A Delft Method Module is affordable. You pay for 5 weeks only and you will not get a discount or refund. Only in case of unforeseen and serious facts, catching up on the missed classes in the next batch is to be discussed.
Better wait for the next starting moment when you know that you must miss more than three classes. However, many students continue joining online classes when they are on business trips, or visiting relatives.
Moreover, you can ask your teacher to record the class. If you do that before 17:00, you'll receive the link to the recording at the end of the evening. The recording will be available 24 hours after the missed class.