Cookies missing from view

missing_cookies.txt

# Form
<input type="hidden" name="_csrf_token" value="<%= @conn.req_cookies["_csrf_token"] %>"/>
<input type="hidden" name="_csrf_token" value="<%= csrf_token(@conn) %>"/>

# First input has the csrf_token value, second input value is blank

# Inside view module, IO.puts prints an empty map %{}
def csrf_token(conn) do
  IO.puts inspect(conn.resp_cookies)
  conn.resp_cookies["_csrf_token"]
end

# Inside the template all of the cookies are present
<p><%= inspect(@conn.req_cookies) %></p>