get_user_by_email! returns a %LibraryApi.Library.User{} not {:ok, %LibraryApi.Library.User{}}, so your case in your controller doesn’t match.

Also, you probably know this, but never store user passwords in the database unhashed.

I’m not a JWT power user or anything but can’t you just do

  def render("token.json", %{user: user}) do
    data = %{id: user.id, email: user.email, username: user.username}
    jwt = %{data: data, sub: user.id}
    token = MyAppWeb.Token.generate_and_sign!(jwt)
    %{token: token}
  end

No need to do this, just update here with more information and we’ll be able to provide a more detailed answer.

Well, let’s think about the control flow you might want. get_user_by_email! uses Repo.get_by!. What happens if it doesn’t return any records? It raises an exception. This means that you’d need to handle it with try / catch in your controller, but this probably isn’t what you want. So I’d get rid of the ! on get_by as well as on get_user_by_email to start with.

So now the question: what does get_by return? Well, it returns either the struct that that you asked for, or nil. So you need to handle the result out of get_user_by_email based on whether the result is nil or not. if is one option, pattern matching on %Library.User{} is another. I’ll leave the actual refactoring of the controller action as an exercise for the reader.

Ah yes, that is correct now, you changed from Joken.generate_and_sign which you had in the previous post to Joken.generate_and_sign!. Joken.generate_and_sign returns a tuple, Joken.generate_and_sign! returns a string. However if you changed that it shoul dhave solved yout :erlang.apply error, so what’s the new error you have?