help to create my first dataflow from a SQL table.

Hi

Please can you help me create my first dataflow from a SQL table.

I have done the following:-

• Installed an instance of Microsoft SQL Server Developer (64-bit) on my laptop
• Created database and table with data
• Created a sqlbrowser username and password
• Enabled TCP and firewall port
• Downloaded and installed on my laptop a On-premises data gateway (personal mode)
• Tested the sqlbrowser, user name, TCP and firewall port, by logging into the instance from another machine and running queries on the database tables.
• In Power DeskTop I have created a PBIX with an imported dataset and report and published it to Power BI services
• Tested the gateway refresh on Power BI services ok. Note the gateway uses my Power BI sign-on and then my sqlbrowser username credentials.

Ok, so now I know everything is working ok I want to create my first SQL dataflow. 

• In Power Bi Services I created a workspace
• Clicked on +Create > Dataflow > Add new entities > Blank query
• Copy and paste in my query from Desktop  (I hidden my real TCP address here for security)

    Source = Sql.Database("123.456.7,89,4321", "Testdata", [CreateNavigationProperties=false]),
    dbo_Products = Source{[Schema="dbo",Item="Products"]}[Data]
    in
    dbo_Products

• When I click “select gateway” the drop down menu says “none”
  So I get the error “An on-premises data gateway is required to connect.”

What am I doing wrong?

Why cant it find my  On-premises data gateway (personal mode)?

Please can you provide detailed instructions because this is my first time using sql dataflows.
Many thanks