url for current page?

I have a linkedIn share button on a blog. Its currently only using a specific url for a specific post. Cant seem to find an answer that works!

<a href="https://www.linkedin.com/shareArticle?mini=true&url=http%3A//bblf.info/blockchain-bugle/blockchain-for-good&title=Blockchain%20for%20Good&summary=&source=">
     <img src="../img/linkedin.png" width="30" height="30" alt="LinkedIn Share">
</a>

How do I make it so it takes the url for whichever post is on the current page?