When you add an organization using the modern app-only authentication method, Veeam Backup for Microsoft 365 automatically grants permissions for Microsoft Entra applications.
Anyway, if you prefer to use a custom application of your own, grant all the permissions as below.
Veeam Backup for Microsoft Entra ID Logs to protect tenant audit and sign-in logs.
After you’ve added a Microsoft Entra ID tenant to the backup infrastructure, you can backup and restore Entra ID resources managed by the tenant.
A log backup repository is a storage area where Veeam Backup for Microsoft Entra ID keeps backups of audit and sign-in logs from protected Microsoft Entra ID tenants.
This Veeam cloud credential is for a Microsoft Azure Blob Object Storage Account with Entra ID authentication connecting to the following sorts of accounts.