There is no update for Lightroom 5.7 that includes HDR. There is an "upgrade" to Lightroom 6 or Lightroom CC that will give you that capability. To upgrade to Lightroom 6 will cost about $79. Or you can subscribe to the creative cloud plan. But these new features will not be part of Lightroom 5.
Thanks for the reply. Clicking the upgrade download button still doesn't take me to the Lightroom 6 upgrade. It takes me to the CC page. I do not want CC.
I just upgraded to version 5 a few months ago, when support for the Canon 7D Mark II was added.
If you want to purchase Lightroom 6, which is the standalone version, go to this website:
Scroll to near the bottom of the page and you will find Lightroom. The steps are:
1. Click on the Buy button.
2. Indicate what version you have. The price will change to $79.
3. Follow the other buttons and choices to complete your purchase.
I've been trying to purchase the upgrade for TWO HOURS. Can't select anything but the full version on the website. Two hours with chat reps, and nothing.