If you are trying to locate the region your tenant is in i.e. the place where Power BI will be storing your data in, this is quite easy to figure out. Simply, login to your Power BI service and click on the help menu and then navigate to “About Power BI” as shown in the snapshot below –
This will display a dialog box as shown below. Second last line as highlighted in green rectangle is showing the data center location where your data is stored in. This might be different for you but for me, this is showing in as North Europe (Ireland).