403 Forbidden error when trying to run the experiment online (on pavlovia)

It looks like your experiments is in a directory called list1 inside a directory called test1.
PsychoPy/Pavlovia assume that there is one experiment per directory.
Your test1 repository currently contains all manners of document, together with a desktop.ini and a ixplorer.exe.
I would encourage you to delete that experiment and try again in the manner I recommended.
Does that make sense?

Alain