Need help understanding order of function calls from Phoenix auth

I’ve got trouble wrapping my head around the order in which functions are called in this snippet (from Phoenix’s authentication):

  token =
    extract_user_token(fn url ->
      deliver_login_instructions(user, url)
    end)

where the two functions are:

def extract_user_token(fun) do
  # extract token
end

def deliver_login_instructions(%User{} = user, magic_link_url_fun)
    when is_function(magic_link_url_fun, 1) do
  # notify user
end

(*) Upon reading the snippet, I thought the call order of the functions with dummy values start from the inside to the outside:

1. deliver_login_instructions(%User{}, "http://example.com/abc")
2. extract_user_token(result of call 1)

However, with the guard of deliver_login_instructions/2 being is_function(magic_link_url_fun, 1) , (*) wouldn’t work.
So, the only way this snippet would make sense is:

1. extract_user_token(url)
2. deliver_login_instructions(user, result of call 1)

In other programming languages, that snippet would be written:

token = deliver_login_instructions(user, extract_user_token("http://example.com/abc"))

Did I proceed this right?