diff --git a/.github/workflows/elixir.yml b/.github/workflows/elixir.yml
index 1f3a7cc..fcad44b 100644
--- a/.github/workflows/elixir.yml
+++ b/.github/workflows/elixir.yml
@@ -12,7 +12,7 @@ jobs:
     name: OTP ${{matrix.otp}} / Elixir ${{matrix.elixir}}
     strategy:
       matrix:
-        otp: ['24.1.7']
+        otp: ['24.3.4.11']
         elixir: ['1.13.0']
     steps:
       - uses: actions/checkout@v2
diff --git a/config/config.exs b/config/config.exs
index c3b2035..b22438b 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -1,6 +1,6 @@
 # This file is responsible for configuring your application
 # and its dependencies with the aid of the Mix.Config module.
-use Mix.Config
+import Config
 
 # This configuration is loaded before any dependency and is restricted
 # to this project. If another project depends on this project, this
diff --git a/lib/keycloak.ex b/lib/keycloak.ex
index 8102a39..2c60cf9 100644
--- a/lib/keycloak.ex
+++ b/lib/keycloak.ex
@@ -33,6 +33,12 @@ defmodule Keycloak do
   @doc """
   Creates a `OAuth2.Client` using the keycloak configuration and
   attempts fetch a access token.
+
+  ## Example
+  Get token based on client credentials:
+
+    get_token!(grant_type: "client_credentials", code: "")
+
   """
   @spec get_token!(keyword(), keyword()) :: any()
   def get_token!(params \\ [], _headers \\ []) do