The StepSequencer module doesn't have a timeIndex input, but here's how to find a new example of how one could go about using a TimeIndex Sound as an index into Arrays of pitches and of gates (1s & 0s):
Kyma Sound Library/Scripts Constructors & Composition/Sequencers.kym
the Sound with the (very long!) name:
TimeIndex Sound through Waveshaper as index into sequence of pitches w/ metric & melodic modulation (Polyphony-4)