Power Bi pro not refreshing the data autimatically

Dear All!

I have a problem with the setup of Power BI (pro version) automatic data refresh. The system answer is the followings:

„The last refresh attempt failed. Your Personal Gateway is offline or could not be reached”

„Details: The last refresh attempt failed. Your Personal Gateway is offline or could not be reached. Ensure the Gateway computer is on and you are logged on to it during the scheduled refresh period.”

Can You help me, how can I set properly this automatic scheduled report refreshing? The test of the data source connection also not running.

Thanks a lot, István