In the Tumblr Editor, open your Account Settings and select Edit Appearance.
On the next page, select Edit Theme.
Click on the Edit HTML link.
Paste this exact script into your Tumblr HTML file. It's best to add it between the Head tags. Once you add the script, click on Update and save.
Create Text Post
Return to your Tumblr Admin page, and create a new Text post.
Paste this shortcode into the post and save. Expand the post, and you'll see your new Facebook Feed plugin. You can edit POWr Facebook Feed by clicking the POWr Settings Icon in the corner.
Edit your Facebook Feed on Tumblr:
Go to the live Tumblr web page and click the Settings Icon in the top right corner of your Facebook Feed Plugin.