Thanks for reaching out!
Based on my research, there is no MS documentation available which can get the value defined for "MaximumDurationInMinutes" using MS Graph API. As it is an Exchange PowerShell property, so the value for this may not be fetched using Graph API.
Please follow these document to know available properties for Calendar resources:
However, calendar resource doesn't accept meetings longer than 1440 minutes. Please do refer a similar post.
Hope this helps.
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