The CLI examples in the readme, like e.g. javascript-obfuscator input.js --output out.js --sourceMap true --sourceMapBaseUrl 'http://localhost:9000' --sourceMapFileName example have the wrong syntax. They use the JS options syntax, instead of the CLI syntax.

The example in this case should be :
javascript-obfuscator input.js --output out.js --source-map true --source-map-base-url 'http://localhost:9000' --source-map-file-name example

I was fighting with this for a bit wondering why the source maps were not generated.