As far as I can see, this requires S3 or a S3 compatible service. Kind of defeats the purpose of self hosting unless you can set one yourself (it may be, I didn't look).
EDIT: Apparently there's a way to use filesystem instead of S3, it's just not well documented.
FWIW, It took me about 5 minutes to get it going after I updated nodejs to version 10. It took me another 5 minutes to realize it setup a local filesystem storage in $TEMP automatically. I was impressed with how easy it was to get going, and that it picked sensible (though not well documented) defaults :)
Data is encrypted at client and a url with a key is generated.
Can be used 'burn after reading or with some specific lifetime.