IFTTT (If This Then That) is a free online tool to automate interactions amongst your favorite apps and devices. Using IFTTT, you can automatically share your latest WordPress blog post to your Facebook account. Follow the steps below to set it up.

1. Create an IFTTT account.

2. On the IFTTT Facebook page, click Connect to add your Facebook account.

3. On the IFTTT WordPress page, click Connect to add your WordPress account.

4. Now, go back to the IFTTT WordPress page and click Automatically share new posts to a Facebook page.

5. Click Connect.

6. Now, when you publish a new WordPress post, IFTTT will automatically share it on your desired Facebook page.