Verify an app service plan exists

To verify the existence of an app service, use az appservice plan show. Below, plan-docprocessor-e357b213 is the name of the service plan.

az appservice plan show --resource-group acr-task-demo --name plan-docprocessor-e357b213
{
  "id": "/subscriptions/<redacted>/resourceGroups/acr-task-demo/providers/Microsoft.Web/serverfarms/plan-docprocessor-e357b213",
  "kind": "linux",
  "location": "East Asia",
  "name": "plan-docprocessor-e357b213",
  "properties": {
    "provisioningState": "Succeeded",
    "status": "Ready"
  },
  "resourceGroup": "acr-task-demo",
  "sku": {
    "name": "B1",
    "tier": "Basic"
  },
  "type": "Microsoft.Web/serverfarms"
}