Go to Account Settings Edit Appearance Edit Theme.
Click on the Edit HTML link underneath Custom Theme.
Paste POWr Script
Paste this exact POWr script into your HTML file, in between the Head tags. Then update and save.
Create New Text Post
Go back to the Tumblr dashboard and add a new Text post.
Paste the Shortcode
Paste the shortcode into the post. Then save. You'll see the new POWr Tabs plugin when you expand the post. Click the POWr Settings Icon to open the POWr Editor.
Begin editing this Tabs Plugin directly inside of your Tumblr website:
Go to the live Tumblr web page and click the gear icon in the upper right corner of the Tabs Plugin.