Here is my platformio config:

[env:m5stack-core2]
platform = espressif32
board = m5stack-core2
framework = arduino
board_build.filesystem = littlefs
monitor_speed = 115200
lib_deps =
ottowinter/ESPAsyncWebServer-esphome@^2.1.0
m5stack/M5Core2@^0.1.0
lorol/LittleFS_esp32@^1.0.6

With that config, I cannot upload files in memory. it always save the file as spiffs.

Auto-detected: /dev/ttyUSB0
Uploading .pio/build/m5stack-core2/spiffs.bin
esptool.py v3.1
Serial port /dev/ttyUSB0
Connecting....
Chip is ESP32-D0WDQ6-V3 (revision 3)
Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse, Coding Scheme None
Crystal is 40MHz
MAC: 84:cc:a8:5f:ea:08
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 460800
Changed.
Configuring flash size...
Auto-detected Flash size: 16MB
Flash will be erased from 0x00c90000 to 0x00ffffff...
Compressed 3604480 bytes to 155100...
Writing at 0x00c90000... (10 %)
Writing at 0x00ca61ce... (20 %)
Writing at 0x00cbe455... (30 %)
Writing at 0x00cd3e90... (40 %)
Writing at 0x00ce9a6c... (50 %)
Writing at 0x00cff565... (60 %)
Writing at 0x00d13a71... (70 %)
Writing at 0x00d2bf09... (80 %)
Writing at 0x00d4a5ce... (90 %)
Writing at 0x00d7257e... (100 %)

It upload succesfully but then fail to access the file from the server.

.pio/libdeps/m5stack-core2/LittleFS_esp32/src/lfs.c:1076:error: Corrupted dir pair at {0x0, 0x1}
E (6257) esp_littlefs: mount failed, (-84)
E (6261) esp_littlefs: Failed to initialize LittleFS
[E][LITTLEFS.cpp:90] begin(): Mounting LITTLEFS failed! Error: -1