Follow these steps to integrate tumblr notification:
1. Customize your blog theme
Tumblr dashboard > Customize
2. Edit HTML
Customize > Edit HTML
3. Copy-paste your NotifyVisitors integration code into Tumblr’s HTML and save
Get your NotifyVisitors integration code from the ‘Notifyvisitors Admin panel -> ‘Integration’ and paste the code just before closing body tag
First login to the site and then copy the code so that the secret keys are already prefilled.