fileaccess with mongoose on platformio with arduino framework

[Mike0675]

I'm using mongoose on both ESP32 and Teensy4.1.
Both programmed in PlatformIO and Arduino-Framework.

Now i'm trying to upload a file to Flash or SD.

I'm using the tutorial #binary-upload-multiple-posts.

mongoose is trying to open the file, but can't. Where can I tell mongoose the file system I want to open?
Can mongoose at all work with arduino-like filesystems?

[scaprile]

Please see our documentation, and follow the guidelines in our tutorials.
https://mongoose.ws/documentation/#filesystem
No idea what an "arduino-like filesystem" is for you, if such a thing exists.