The comdirect bank doesn't offer the TAN-procedure 'photoTAN push' via FinTS. As the Outbank app communicates via FinTS with the bank, photoTAN push cannot be used in the app. 

Allegedly, comdirect bank is already working on this feature: https://twitter.com/comdirect/status/1255033113098498048 

Alternatively, you can use mobile TAN or photoTAN for authorization.

To find more information about photoTAN, go to https://help.outbankapp.com/de/kb/articles/kann-ich-das-phototan-verfahren-in-outbank-verwenden