base58Encode error: 'Object(...) is not a function'

Hi, I'm trying to use the base58Encode() function but with no success. I get the error: `TypeError: Object(...) is not a function`

My code snipet
```
const bytes = stringToBytes('My Message')
const uint8Array = new Uint8Array(bytes)
const encodedMessage = base58Encode(uint8Array)
```

Thanks!
