Not able to access website through heroku

I am trying to scrap the "https://ift.tt/2Yqo5VY" website for some data using htmlUnit in java in spring boot application. I have hosted it on heroku, i am able to access the website locally but not on heroku.

Error from heroku logs: You don't have permission to access "https://ift.tt/34laumx" on this server.