Warning popup for missing attachments

Summary:

We need a warning popup for missing attachments during submission to the Preparer, specifically for reconciliations other than those with a zero balance.

I created an alert in a specific format and selected Restriction = None because I only want a warning, not a workflow block. However, the alert only appears on the screen when I choose a restriction like Prevent Workflow. If I leave the restriction as “None,” the alert is only visible after clicking the Alert icon.

My requirement is for the user to see a warning message on the screen immediately when the conditions are met and user is submitting the reconciliation,