There is no need of creating any pub id just copy it from your adsense account if you have it. Just follow the steps given below-
1. Go to www.google.com/adsense
2. Sign in your account in which your adsense
application is approved.
3. Go to adsense setting.
4. There you will find one of the id for example- pub-79812789 something like that.
5. Just copy that pub id.
6. Now go to techulator and go to forum and click on associate your adsense account and enter your pub id and save it.
Now you have done it and now start posting articles and win some cool cash.