How could I increase my one special product sale, which is for author?

Recently, I have released a WordPress plugin for product licensing. Basically this product is for author. It has full licensing system, product update management system, enavto purchase code verification system, auto license script generation system and a full set of API, by this api you any 3rd party application can access/create its data. It has also a web hook (instant notification system), by on new license or client creation it will call those remote URL which you have added into web hook setting.

I have worked a lot on this, if you see the plugin you could understand how hard I work. But it’s sales rate is disappointing me.

Expecting some tips form experts

I couldn’t understand, how should I do a marketing, cause this product is for author.

Please give me some suggestion

Sarwar Hasan