Which permission specifically? They all seem valid for what the app does (and most are not present in app or disabled by default)
Location - for providing localized content (disabled by default)
Personal Info - for providing log in and personalizing content (questionable)
Financial Info: For in app payment/subscription (disabled by default)
Health - for personalizing content (not present in app and could be mislabeled by me)
Messages - For automating 2 factor auth (disabled by default)
Photos - For sending photos and videos (disabled by default)
Audio - For sending audio (disabled by default)
Files - For sending and saving files (disabled by default)
Calendar - Not 100% sure, but some guesses could be content personalization and/or time based events in app (could be mislabeled by me) (disabled by default)
Contacts - For establishing your social network (disabled by default)
App activity - This could be suspect for sure, but also useful as a troubleshooting/debug mechanism (not present in app)
App info and performance - troubleshooting/debug mechanism
Device ID - Security, Ad personalization
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That said, I just installed in on my Android device and some considerations:
1) The suspect permission (App Activity) is not requested or present in the permissions list. Nor is health. Financial is better worded in that it is requesting "Google Play billing service"
2) Only Notifications permission is enabled by default. Camera, Contacts, Location, Microphone, Photos and Videos, etc are all explicitly disable, presumably till needed by the app at some point (meaning you'll know when and why they make use of it).