@among Sure, just go to Settings - Plans.
@Tutanota I'm in there, I have atrached an image that's all I can see. There is no upgraded option.
@among Could you try updating your app? Possibly you need to update F-Droid first (if you get the app from there).
@Tutanota The latest one is not available there unfortunately.
@among You can also upgrade in the web client, you will have all the features in the app already - even if it's not updated yet.
Gregory's Server
@Tutanota I'm in there, I have atrached an image that's all I can see. There is no upgraded option.