Using un-managed identities for Azure PostgreSQL Server may make user management challenging.
At this time, the console UI does not have remediation steps available. For possible CLI remediation, see the product documentation (below) or use Terraform.
In Terraform -
References:
https://learn.microsoft.com/en-us/azure/postgresql/single-server/how-to-connect-with-managed-identity
https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/postgresql_server#identity