Error with meteor-buildpack-horse.git

Hi Team

Staging app and tracing logs…
Downloaded app package (6.8M)
-----> Listing HEROKU_ environment variables
HEROKU_APP_ID:
HEROKU_APP_NAME:
HEROKU_DYNO_ID:
HEROKU_RELEASE_VERSION:
HEROKU_SLUG_COMMIT:
HEROKU_SLUG_DESCRIPTION:
FATAL: ROOT_URL is not defined.
Failed to compile droplet: Failed to compile droplet: exit status 1
Exit status 223
Cell 4201c352-f76f-43e9-ba03-c7564989050b stopping instance f2bf6cca-4a48-446c-b411-cc2163ab8b66
Cell 4201c352-f76f-43e9-ba03-c7564989050b destroying container for instance f2bf6cca-4a48-446c-b411-cc2163ab8b66
Cell 4201c352-f76f-43e9-ba03-c7564989050b successfully destroyed container for instance f2bf6cca-4a48-446c-b411-cc2163ab8b66
Error staging application: App staging failed in the buildpack compile phase
FAILED

Kindly let me know where is “ROOT_URL” to be configured for Meteor.

Build pack ```
cf push -m 512M -b https://github.com/RocketChat/meteor-buildpack-horse.git

https://rocket.chat/docs/installation/paas-deployments/heroku/#customized-command-line-for-developers

ROOT_URL should be the path to your app:
ROOT_URL=https://<your app name>.herokuapp.com/