In Qlik Sense, the data sources are defined as data "libraries". In this case, you will have to declare that URL as a data connection (web data) in the data connection pane.
You need to create a Data Connection and select Web File.
Then, paste the URL from QVSource (not the entire load script, but just the URL in the FROM clause).
After that, you will see the Web File connection available in the right pane: