%{ flasked: [ info: ~S""" If you can read this, than you have not configured your release/app in a way to load the correct mapping file. Please consult the documentation for Flasked: iex(0)> h Flasked Or have a look at the README.md of Flasked. """, x_example: {:flasked, :FLASKED_X_EXAMPLE, :dict_of_integers, [error: "No ENV var was set."]} ] }