Macaroon.create_macaroon

You're seeing just the function create_macaroon, go back to Macaroon module for more information.
Link to this function

create_macaroon(location, public_identifier, secret)

Specs

create_macaroon(binary(), binary(), binary()) :: Macaroon.Types.Macaroon.t()

Create an empty Macaroon with a provided location, public_id and secret