You manage three projects tied to one billing account and need a budget alert for Compute Engine usage on one project. What should you do?

To create a budget alert for a specific project, you need the Billing Account User role (or a custom role with equivalent permissions) on the billing account. This role allows you to create and manage budgets. The process involves navigating to the billing section, selecting the relevant billing account, and then creating a new budget. During budget creation, you can specify the scope to a particular project and configure alert thresholds. The option "create a budget plus a custom alert" is redundant as budget creation inherently includes alert configuration. "Project administrator" is insufficient as it doesn't grant billing account permissions.