You have to select the workspace ID (
$workspace.CustomerId), not the whole object (
$workspace = Get-AzoperationalInsightsWorkspace ` -Name *******-cac-ws-security-01 ` -ResourceGroupName *******-cac-rg-security-logs-01
I changed the variable name in your question from "$workspaceid" into "$workspace" without changing what's in it. And assume you've defined
$query for the same KQL query.
Then run a very similar command:
Invoke-AzOperationalInsightsQuery -Query $query -WorkspaceId $workspace.CustomerId