With thorough reading, I figured a " " is necessary when entering the token.
It is all good now!
GITHUB_TOKEN = "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"
headers = {"Authorization": f"token {GITHUB_TOKEN}"}
I proposed the this edit in the GitHub training repository - Line 125
Thank you!