Describe the current behavior
Just got a 403 error when trying to launch tensorboard in colab.

Screenshot:

and when i try directing from the site (e.g. https://0g3k40fl0s271-496ff2e9c6d22116-6006-colab.googleusercontent.com/?tensorboardColab=true), it doesn't get a 403 error:

I have enabled third-party cookies like in the screenshot:

Describe the expected behavior

1. from this notebook https://colab.research.google.com/github/tensorflow/tensorboard/blob/master/docs/tensorboard_in_notebooks.ipynb
2. I execute the cell here:
   
   and there:
   
   seems like an iframe issue.

What web browser you are using
(Chrome, Firefox, Safari, etc.) Google Chrome Version 116.0.5845.180 (Official Build) (64-bit)

Additional context
Link to a minimal, public, self-contained notebook that reproduces this issue.

• Share the file using your GitHub account using File > Save a copy as a GitHub Gist.
• or Share Drive notebooks using the Share button then 'Get Shareable Link'.
  https://colab.research.google.com/github/tensorflow/tensorboard/blob/master/docs/tensorboard_in_notebooks.ipynb