diff --git a/.env.development.local.example b/.env.development.local.example
index 236ba7874..0be5a67d2 100644
--- a/.env.development.local.example
+++ b/.env.development.local.example
@@ -10,6 +10,9 @@ GITHUB_CLIENT_SECRET=
 # Path to github private key file (relative to root of this project). If at the root, just specify filename
 PRIVATE_KEY_PATH=
 
+# The URL for the local domain obtained after tunneling (ex. `https://__MYDOMAIN__.public.atlastunnel.com` or `https://XXXX-XXX-XXX-XXX-xX.ngrok.io`)
+APP_URL=
+
 # The Jira Instance URL you created for this app (ex. https://example.atlassian.net)
 ATLASSIAN_URL=
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 7dc0dfc31..3d6f55cd9 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -81,6 +81,8 @@ Once you've set up your GitHub app and cloned this repo, copy the file `.env.dev
 + `ATLASSIAN_URL`: The URL for the Jira instance you're testing on. If you don't have one now, [please set the value of this variable from the steps mentioned here](#create-your-jira-instance).
 + `APP_KEY`: Your Jira app key - need to be unique for your development app
 + `WEBHOOK_SECRETS`: `["development"]` as previously set up in the GitHub app page.
++ `APP_URL`: The URL for the local domain obtained after tunneling. This should be the same as the `Domain` value set when you [configured your GitHub App](#configuring-a-github-app)
+(ex. `https://__MYDOMAIN__.public.atlastunnel.com` or `https://XXXX-XXX-XXX-XXX-xX.ngrok.io`)
 
 Lastly, you need to replace the value of the follow variables in the global `.env` file: