Add a Flickr feed.

1. To do this you will need to get your user id from here https://www.webpagefx.com/tools/idgettr/.

Once you have it find the Flickr UserID box and paste it in.

2. Final step would be to turn https/encryption off so the feed works. Can be found in your blog settings i.e. – https://www.tumblr.com/settings/blog/yourusername