If this is a commercial product, then I recommend you don't. It will almost certainly be classed as spam, and that means your account will probably be terminated.
If it isn't commercial, but free for use and you are prepared to post the source, then an article is welcome. It's easy to post - just follow the instructions under "Submit an article" on the "Articles" menu in the top right of this page. There are some guidelines there which may help. You can also post any requests for help in the Article writing forum
Have fun writing it, and I hope to review it for publication soon! But...If you just want to use this as free advertising, then you will probably get short shrift indeed!
"Yes this is a commercial product. I saw on the code project about third party vendor showcases, that is the reason I was wondering what is the best way to showcase the product on the code project. Even though this is commercial we are giving 1 month free trial period, where the users will have the full functionality of the product."
Then you really shouldn't write an article on it. The actual article will be seen as an advert (and they charge people for advertising) so your account would not last long, and all the work you put into the article would be wasted. The other risk is that you could put some of your company IP into the article, and since all code published here is subject to one of the licences
] allowed that would put it into the public domain and freely available for others (including your competitors) to read, use and modify.
Unless this is your company business model (and I doubt it somehow) there could be some serious shouting going on in senior management offices when people find out...