You have Acronis Backup Cloud 7.7. Local backup is enabled for a customer. However, the customer cannot select any local destination in a backup plan; all local storages are greyed out.
Issue in the product.
The issue will be fixed in the next update of Acronis Backup Cloud. This article will be updated as soon as the fix is available.
As workaround, manually disable local backup offering for the particular user and then enable it again. See this article for instructions.