Hi @gihyun Park ,
Thanks for posting in our Q&A forum.
It seems impossible from server side.
From client side, it is suggested that you can export your calendar items to a .pst file and then import them to your archive folder.
And a source explains how you can use the AutoArchive feature in Outlook to move items from your active folders to an archive folder. Please refer to: https://support.microsoft.com/en-us/office/autoarchive-settings-explained-444bd6aa-06d0-4d8f-9d84-903163439114
I'm not clear how to implement by EWS.
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