Can you use https://github.com/rust-nostr/nostr Kotlin bindings ?
Discussion
Most likely
Last release of bindings not include the NWC client yet (in rust is already available).
Approx. in a week I'll release the new version that will include it:
nwc = NWC(uri)
nwc.pay_invoice(..)
nwc.get_balance()
...
Ah, my bad. For Zeus is not needed that client 😅
Anyway, I'm planning to build an implementation also for nodes (hope to include it in next release)