Can't save slide deck from Python API into a folder?

Hi Team,

I can’t seem to get a presentation I’ve created into the folder I’d like to save it to. The last line of my code is (‘folder’ is not the actual folder name):

pres_url = py.presentation_ops.upload(my_pres, sharing='secret', filename = 'folder/folder/Implem_Pres')

However, this hangs for a really long time before it returns two errors:
JSONDecodeError: Expecting value: line 1 column 1 (char 0)
PlotlyRequestError (followed by several hundred lines of HTML).

The folder path exists (I’m not trying to create it), and this formatting of filename works for all of the plots i’ve created.

The exact same code, without the folder path, works perfectly (i.e., returns the URL of the presentation).

pres_url = py.presentation_ops.upload(my_pres, sharing='secret', filename = 'Implem_Pres')

This makes it seem like it’s not an authentication error. I’ve tried manually moving the presentation into the folder before rerunning the code with no luck.

What am I doing wrong?