@Handian Sudianto Thanks for reaching out to Microsoft Q&A.
In the above, I was taking about the egress traffic limits for Azure Virtual machines and Azure App service.
As I understand that you want to know the amount of traffic that is being served by particular service.
For Virtual Machines, you can make use of Network Out
azure monitor metric to calculate the outbound traffic in bytes. You can refer to this documentation for supported metrics in azure monitor.
Here is the sample image for your reference, In the below image we have calculated the total amount of network out by a single virtual machine in the last 30days span.
For Azure App service, you can refer to the BytesSent
Azure Monitor metric to understand more on outgoing bandwidth used across all the instances.
Here is the sample screenshot, for your reference :
Feel free to reach back to me if you have any further questions on this.