Hi,
I tried to reproduce a pretty similar scenario as the one displayed in the following video. PowerApps custom visual for Power BI V2 and see what I could come up with.
I should point out that the PowerApps applicatoin was a totally new one built all-from-scratch. The PowerApps DataSource used in the scenario was an Azure SQL Database - in a same way as shown in the video. I could later connect the Power BI report to the very same Azure SQL Database in DirectQuery mode, so that any new data added from a user in the PowerApps form would be instantly detected in Power BI report. I did manage to make it mostly work - except for the PowerBIIntegration.Refresh() part added in the submit button OnSelect option. I ended up with an error message the method was not recognized therefore not supported!! Maybe I missed something. Any help on how to cope with it would be appreciated. Thank you