Autopilot disks may be free or bundled based on the usage tier, which is why they might not show up as billable usage. Are you using a GCP project under the free trial? Also, have you already followed the steps below?
Go to IAM & Admin > Quotas.
Filter by Persistent disk regional (or zonal depending on your region).
Select the quota to increase (e.g., “Standard persistent disk (GB)”).
Click Edit Quotas > fill the form > include your billing account ID and justify the need.
If this still isn’t working, please try contacting to the Google Cloud Support team .