(1) First you need to use the set-place Exchange Powershell cmdlet to set the values for your exchange online mailbox and update its metadata info. Related documentation - https://learn.microsoft.com/en-us/powershell/module/exchange/set-place?view=exchange-ps
(2) Now make the Graph API call and it works for me.
(If the reply was helpful please don't forget to upvote or accept as answer, thank you)