diff --git a/README.md b/README.md
index 9ef0ec4..a8dce58 100644
--- a/README.md
+++ b/README.md
@@ -29,6 +29,22 @@ By deploying a GitHub App and asking their students to install this app on their
 1) You need to [create a GitHub App](https://docs.github.com/en/developers/apps/building-github-apps/creating-a-github-app) in your organization or personal account on GitHub
 2) For GCP cloud run deployment, you may need to install terraform and the gcloud CLI.
 
+## GitHub App
+
+Your GitHub App needs the following informations :
+
+### Repository permissions
+- Actions: RO
+- Checks: RW # create a check on PR
+- Issues: RW # comment the issue
+- Contents: RO
+- Pull requests: RW # comment the issue
+
+### Subscribe to events
+- Pull request
+- Push
+- Workflow job
+
 ## Deploy locally
 
 You first need to create a `.env` file by filling up the values from the `.env.template` file.
diff --git a/github_tests_validator_app/config.py b/github_tests_validator_app/config.py
index 40cf6d3..2bc54f2 100644
--- a/github_tests_validator_app/config.py
+++ b/github_tests_validator_app/config.py
@@ -6,7 +6,7 @@
 import google.cloud.logging
 import yaml
 
-if os.getenv("LOGGING", "") == "GCP":
+if os.getenv("LOGGING", "").replace("\r\n", "") == "GCP":
     logging_client = google.cloud.logging.Client()
     logging_client.get_default_handler()
     logging_client.setup_logging()
@@ -23,17 +23,19 @@
         logging.getLogger("uvicorn").removeHandler(logging.getLogger("uvicorn").handlers[0])
 
 # GitHub
-GH_APP_ID = cast(str, os.getenv("GH_APP_ID", None))
+GH_APP_ID = cast(str, os.getenv("GH_APP_ID", None)).replace("\r\n", "")
 GH_APP_KEY = cast(str, os.getenv("GH_APP_KEY", None))
-GH_PAT = cast(str, os.getenv("GH_PAT", None))
-GH_TESTS_REPO_NAME = cast(str, os.getenv("GH_TESTS_REPO_NAME", None))
+GH_PAT = cast(str, os.getenv("GH_PAT", None)).replace("\r\n", "")
+GH_TESTS_REPO_NAME = cast(str, os.getenv("GH_TESTS_REPO_NAME", "")).replace("\r\n", "")
 GH_TESTS_FOLDER_NAME = "tests"
 GH_WORKFLOWS_FOLDER_NAME = ".github/workflows"
 GH_API = "https://api.github.com/repos"
 GH_ALL_ARTIFACT_ENDPOINT = "actions/artifacts"
 
 # Google Drive
-GDRIVE_MAIN_DIRECTORY_NAME = cast(str, os.getenv("GDRIVE_MAIN_DIRECTORY_NAME", None))
+GDRIVE_MAIN_DIRECTORY_NAME = cast(str, os.getenv("GDRIVE_MAIN_DIRECTORY_NAME", "")).replace(
+    "\r\n", ""
+)
 
 # Google Sheet
 GDRIVE_HIERARCHY_PATH = "github_tests_validator_app/data/gdrive_hierarchy.yml"
@@ -60,4 +62,4 @@
 # Common
 CHALLENGE_DIR = "tests/tests/"
 DATE_FORMAT = "%d/%m/%Y %H:%M:%S"
-USER_SHARE = os.getenv("USER_SHARE", "").split(",")
+USER_SHARE = os.getenv("USER_SHARE", "").replace("\r\n", "").split(",")