I think as long as you follow the rules and regulations related to this site and article section, no separate permission is required for posting an article. But before doing that I advise you to go through all the articles which are on the top of the article index which will give you a good idea about the methodology, terms and conditions and other required information useful for a member to post an article. After you post the article, the editor's will review the article. They may directly approve and show it in the articles section. They may keep it pending and ask you to do some modifications. Then you have to do those corrections and resubmit. Then the editors will approve and publish. The article may get rejected also and they will give you the reasons for rejection also.
So you can try posting and all the best to you.