no it is separate from lightning, but works with lightning.
Discussion
Is it a token?
there is no "Cashu Token" or offering or exchanges. it is federated custodians hosting lightning nodes. lightning bitcoin in > ecash > lightning bitcoin out.
Cashu.space is an ecash system built on lightning
it let's you anonymously transact through a custodian using blind-signature cryptography
a cashu faucet trickles cashu tokens, so plebs can try it for free
gandlaf.com/faucet