The generate-mnemonic command

zallet generate-mnemonic generates a new BIP 39 mnemonic and stores it in a Zallet wallet.

The command takes no arguments (beyond the top-level flags on zallet itself). When run, Zallet will generate a mnemonic, add it to the wallet, and print out its ZIP 32 seed fingerprint (which you will use to identify it in other Zallet commands and RPCs).

$ zallet generate-mnemonic
Seed fingerprint: zip32seedfp1qhrfsdsqlj7xuvw3ncu76u98c2pxfyq2c24zdm5jr3pr6ms6dswss6dvur

Each time you run zallet generate-mnemonic, a new mnemonic will be added to the wallet. Be careful to only run it multiple times if you want multiple independent roots of spend authority!