Hello @Ankur Gupta,
Thanks for reaching Microsoft.
I tested the API and was able to replicate your issue. Ideally, the least privileged permission should suffice. I suggest you to submit the content feedback request from within the document, briefing this inconsistency of technical information in the document. Please use the feedback option as highlighted in the screenshot below:
Meanwhile, you can use the ChannelMember.Read.All permission to access this API.
Documentation references:
https://video2.skills-academy.com/en-us/contribute/content/provide-feedback
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