Yes, if you have a valid credit card added to you account.
With extended rental you can have a bike for six hours, in addition to the included 60 minutes. After 60 minutes it costs 5 NOK per 15 minutes.
Does the money get drawn from my account automatically?
Yes, if you have a valid credit card connected to your account. You'll always have a good overview of how long you've been out riding and when extend rental kicks in in the app.