If your subscription allows for Agentless Backups for Office 365, then a local Backup Agent is not required.
Instead, you will need to grant the Acronis application access to your data in Office 365 for backup.
You will need to have access to a Global Administrator of your Office 365 tenant to grant the required permissions.
Configure Agentless Backups for Office 365
The Acronis Cyber Cloud service will pull through details for users, groups and sites for your Office 365 service. This can take some time.