Readme example returns Heroku Application error

GET  `https://carbonnowsh.herokuapp.com/?code=Made+with+Love+in+India+by+Sumanjay&theme=darcula&backgroundColor=rgba(144, 19, 254, 100)
`

returns: 

"Application error
An error occurred in the application and your page could not be served. If you are the application owner, check your logs for details. You can do this from the Heroku CLI with the command"