When using the SparkFun ESP32 Things Plus it I get this error when I select the large_spiffs partition. Also, when I use the default selection for 16mb partition it will flash the default esp32 partition and not the default_16MB partition scheme. To replicate it just select the SparkFun ESP32 Things Plus under the board in the IDE and try and flash the littlefs, you don't need a board connected to see it is using the wrong partition. I checked the boards.txt file in the C:\Users\matt\AppData\Local\Arduino15\packages\esp32\hardware\esp32\3.0.7\boards.txt and the board does reference the correct partition, but it seems that this extension isn't.

LittleFS Filesystem Uploader v1.5.0 -- https://github.com/earlephilhower/arduino-littlefs-upload

Sketch Path: C:\Users\matt\Documents\Arduino\ESP32_Now_AP_Test_V8
Data Path: C:\Users\matt\Documents\Arduino\ESP32_Now_AP_Test_V8\data
Device: ESP32 series, model esp32
Using partition: large_spiffs
Partitions: C:\Users\matt\AppData\Local\Arduino15\packages\esp32\hardware\esp32\3.0.7\tools\partitions\large_spiffs.csv

ERROR: Partition file not found!