This can be done via delegate access. Delegate access let you accept and send invites on behalf of someone else. For that the other person needs to provide you delegate permissions.
You can grant a delegate permission to read items in your folders or to read, create, change, and delete items. By default, when you add a delegate, the delegate has full access to your Calendar and Tasks folders. The delegate can also respond to meeting requests on your behalf.
For help, check the link:
office.microsoft.com/en-in/outlook-help/allow-someone-else-to-manage-your-mail-and-calendar-HA102749417.aspx
Accept meetings on behalf of someone else - Delegate Access: Let someone else mind your busyness