With @egekorkan I have discussed this issue. I tried to run the example oauth code provided. I have not changed any code and simply followed the instruction mentioned in the Readme.md file but nothing was getting printed when I ran the consumer.js file. Then I enabled the debug level so that the exposer.js can print the log and I saw the following error:
'node-wot:cli:cli:error WoT-Servient cannot start. Error: Servient does not support thing security schemes. Current scheme supported: OAuth secCandidate'

https://github.com/eclipse/thingweb.node-wot/tree/master/examples/security/oauth