The One’s EXPRESSION ASSIGN section allow you to quickly assign several commonly used modulation sources to any available destination. However the One can actually use many more sources, including the noise envelope.
To access these, select the MOD button under the display and you will see the various modulation lanes that are currently in use or that are available. To create a new one with the noise envelope as a source, use the large encoder knob to navigate to a new lane and then use the first soft knob to change the source to NOISE EG. Once selected you can click the encoder knob and change the amount of the modulation, as well as setting the destination and adding a controller or transform to the modulation lane if you wish.