The recommended method for working with Azure is always PowerShell. The Azure portal and SSMS are tools there for your convenience but they do not scale well. If you have multiple databases to migrate, potentially from multiple servers, using PowerShell will be much more efficient. Scripting your Azure work makes it repeatable and works towards the Infrastructure as Code concept.
In this demonstration, the below steps will be used.
Export the bacpac file to a local directory with sqlpackage.exe.
Copy the bacpac to Azure Blob Storage with AzCopy.exe
Use the PowerShell AzureRM module and cmdlets to create an Azure SQL Database from the bacpac file.
Derik shows the point-and-click way as well as the Powershell way.