GitHub Jira Integration redirect URL to GitHub leading to 404

[Benjamin Paz]

1) Created a service account in GitHub that has ownership of our GitHub team.

2) Jira app (by GitHub) installed.

3) Defined an OAUTH app in GitHub for Jira Cloud to have access.

Then on our Jira cloud account, in the DVCS account "Add new GitHub Enterprise Account" enter  1 the name of the service account, 2 Host URL, 3 Client ID and 4 Client secret.  Clicking "Add' and then "Continue" buttons lead to 404 on GitHub site.

Our organization is "platinum". Is that the problem? Do we need to upgrade to "Enterprise"?