Noobiest question ever

[Pepe le Moko]

Hello, i have the noobiest question ever.

I can't figure out how to spend the renown i have on the U Boat screen. To get new crew in the barracks, there is an enlist button when you click on a seaman or officer but nothing on the U Boat screen, i can't get new torpedos even the ones that don't cost renown or get a new sub.

Yes i know, rtfm but there is only a pdf in the version i bought and it doesn't explain much.