No, since the master password was assigned and confirmed by you personally during the initial use, it is only known to you and can not be reseted by the Outbank support.
It is not possible to change or circumvent the password from "outside".
If you forgot your Master Password, please delte the local data base on your Mac:
- Open the Finder
- Click on "Go to", press the Alt-key and choose "Library".
- Now you are in the ~/Library please search the foulder Containers/com.stoegerit.outbank.osx/
- Delete the foulder com.stoegerit.outbank.osx
Then you can start the app again, enter a new Master Password an enter your bank credentials again.