You'll need to draw some notes in the piano roll to give the Dual Arp something to work with.
The "Arp Note Rate" controls how much the LFO will affect the speed/tempo of the Dual Arp.
The "Transpose Rate" controls how much the LFO will affect the Transpose of the Dual Arp. When you start turning this to the right, you'll start getting more notes added to your arp pattern (beyond the normal 4 note limit).
Video is here:
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