All tours you planned with komoot have the required data for voice navigation. That means you can open them in the app and can let yourself be navigated by clicking on "Navigation" with voice navigation.
Recorded and GPX files imported as recorded Tours cannot be used with voice navigation. Why? You can record your Tours anywhere you have a GPS signal. That means: also on a lake or offroad, where we cannot give you navigation instructions. To make a recording usable for offline navigation, you therefore have to turn it into a planned tour first via our website. Each Tour comes with a button "Plan similar", you can use for that purpose.