Currently, the only option is to extend current subject(s) subscription and add KooBits English as a combined 2 or 3 subjects subscription.
There are benefits of doing so.
1) All subjects will be in one single login account and there is only 1 single subscription to manage.
2) All the subjects will end on the same date and you only need to remember 1 date instead of multiple end dates.
3) You can use this opportunity to make the purchase and sync your preferred end date of all the subjects based on academic period.
4) Enjoy the best deal as a bundle customer.