If you use a third party provider for Hosted Exchange, you may need their help to enable Impersonation for your service account. Impersonation is typically less common than delegate access, but a better fit for giving permissions to applications like Robin.

Most providers we've worked with have self-serve management for Delegate access, but ask you to file a support ticket for activating Impersonation. You can use the following email template as reference. Feel feel to CC support@robinpowered.com -- we're happy to tag in for technical questions. 

Hello,

We're on your [Hosted Exchange product here] and I'd like to get our [Service account email here] service account to have Impersonation rights for resource mailboxes. A few of the apps we use require Impersonation rights in order to manage resources, and they won't work with Delegate access.

Ideally this policy would be based on mailbox type, as we may add more resources in the future. Here's a rough management scope for reference:

New-ManagementScope -Name "ResourceMailboxes" -RecipientRestrictionFilter {RecipientTypeDetails -eq "RoomMailbox" -or RecipientTypeDetails -eq "EquipmentMailbox"}"

Happy to provide additional info if needed. Can you help us enable Impersonation for this account please?