FB sharing button to access extra content on site

Hi freelancers. I'm looking for a talented provider to add a Facebook sharing tool to my site. My website offers free and paid internet/email readings for Osiris, tarot etc. I would like some sort of gateway added to a part of my website so for a person to access the page where they input their question for a free reading, first they must click a button which automatically shares the website (or the Facebook page) on their timeline. They cannot access the form until they have first shared. Once they have clicked the button, and dealt with the Facebook permissions, it will automatically redirect them back to the form for them to claim their free reading. Please mention the word osiris in your bid to show you have read and understand the project requirements. :) For the right provider, this will be an easy task. Extra info: The website is run on a Wordpress Platform with a paid theme. FTP access can be granted if needed Ideally I would like to get this done for $50 or less. Thanks! Please message me if you have any questions or are unclear of something.