Hey there! I think this is a matter of your goals. If your goal is to actually run the distance of a 5k then repeating the training and working on your speed would make sense.
On the other hand if what you're looking for is improving your endurance and general health, then you can perfectly continue with the next trainings increasing the time. Maybe once you achieve the 30min run, you'd like to consider working on your speed right then.
I'd say choose considering your goals and how you think it'll motivate you to continue working hard!
Best of luck and don't stop running ☀️