1. Make a change to the database.  E.g. add a new stored procedure:

CREATE PROCEDURE sprTest 
AS
BEGIN
    SELECT 1
END

2. Go back to the SQL Change Automation window.

3. Navigate to 'Generate migrations'

4. This will show you all the changes made to your database that haven’t been written to the SQL Change Automation Project yet. You can click on an object in the to see the exact differences. The text in the lower left shows the object in the database and how it differs to what’s in the SQL Change Automation Project (text on the bottom right).

5. Click Generate migrations in the top right corner.

6. After the changes are written to the SQL Change Automation Project, you should see a success message.