ERR_NGROK_SHIP_GITHUB_REPOSITORY_NOT_ALLOWED: Your GitHub user cannot see repository REPOID through installation INSTALLATIONID - ngrok documentation

What does ERR_NGROK_SHIP_GITHUB_REPOSITORY_NOT_ALLOWED mean?

ngrok returns ERR_NGROK_SHIP_GITHUB_REPOSITORY_NOT_ALLOWED with this message:

Your GitHub user cannot see repository <REPOID> through installation <INSTALLATIONID>.

Where can I get more help with ERR_NGROK_SHIP_GITHUB_REPOSITORY_NOT_ALLOWED?

Email support@ngrok.com and include the error code.