@Scott Gao , thank you for reaching out to us. Happy to help. I see that you want to know real time cost/billing in your Azure subscription. Currently, we don't have that feature. But, you can create a feature request here.
For now, I would recommend you to leverage Azure Pricing Calculator to estimate your up-front cloud costs. Further, you can check out Estimate the cost of your solution, Analyze and manage your costs, How to optimize your cloud investment with Azure Cost Management and Common cost analysis uses for details about how you can best use the available resources for planning your costs.
Using Cost Analysis, you can get different kinds of advanced usage views (Forecasts and Actual costs) for Days/Accumulated/Service-wise, etc.:
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