Edit Appearance Edit Theme
In your Tumblr dashboard, open your Account Settings. Select Edit Appearance and click Edit Theme.
Go to Edit HTML.
Paste the Script
Paste this script into the Tumblr HTML file. It's always best to paste it between the Head tags. Once you add the script, click Update and save.
Create a new Text post in the Tumblr dashboard.
Paste this shortcode into the post. Expand the post, and you'll see your new Flickr Gallery plugin. Click the POWr Settings Icon to set up POWr Flickr Gallery.
Start to edit the Flickr Gallery Plugin:
Visit the live Tumblr website and click the settings gear in the upper right corner of your Flickr Gallery Plugin.