Unable to open a private repo in Stackblitz

[tim-pod]

We have a Team 210 account which says it includes collaboration on "private GitHub repositories without any additional configuration". However, it has not been easy to determine how to use this feature.

I generated personal access token with the specific permissions:
"Tokens (classic)", repo (full control of private repositories) & read:org (read organization data, under admin:org section)

Then I open the repo with https://stackblitz.com/github/USERNAME/REPO?token=TOKEN

However, I encountered issue when doing this:

The next morning, trying this shows a different error now:

This repo does indeed exist.

Is this a temporary error, and this is the expected method for using private GitHub repos, or is there another method, or documentation on other methods to do this?

Thanks in advance.

[tim-pod]

Feature added.