Starting from Exchange 2019 Cumulative Update 12, there's an option to install only the Exchange Management Tools to create/update/remove recipients in an Hybrid environment. This negates the requirement for running a resource-hungry On-Premises Exchange Management Server. I expect more and more organisations will want to start using this.

For HelloID Provisioning this means that Remote PowerShell can't be used anymore to create/update/delete Remote Mailboxes for mailboxes in Exchange Online, since there's no full Exchange Server anymore in this scenario.

HelloID can support this configuration by requiring the Exchange 2019 Management Tools to be installed on the system where the HelloID Provisioning Agent is running on. The provisioning process should then use the locally installed Management Tools to perform the Exchange Recipient tasks.

Please see https://docs.microsoft.com/en-us/exchange/manage-hybrid-exchange-recipients-with-management-tools