Currently tx's only work with Emulator, usage of API is prevented by type constraints here:
https://github.com/aleeusgr/potential-robot/blob/7bd7935d892f94096dbb609f471667beb3bd847e/src/vesting-cancel.ts#L20-L24

Change the here and in submit tx to be WalletEulator | Wallet and NetworkEmulator | Network (something like it, see Helios docs);

test it:

• can lock with emulator
• can lock with testnet
• can cancel with emulator
• can cancel with testnet.