That tool (AKA "plugin") can only be used with Arduino IDE 1.x.
Arduino IDE 2.x is a complete rewrite of the Arduino IDE on a different framework and in a new language. The "Tools" system of Arduino IDE 1.x used by the arduino-esp32fs-plugin tool you are attempting to use is very specific to the Java language that version series of Arduino IDE was written in, so it was not possible to add support for Arduino IDE 1.x Tools to Arduino IDE 2.x.
Full support for making equivalent (and even better) expansions on the default capabilities of Arduino IDE was recently added to Arduino IDE. However, it will still be necessary for the community to create Arduino IDE 2.x extensions to replace the Arduino IDE 1.x tools, and as far as I know nobody has done that yet for the "ESP32 sketch data upload" Tool.
For now, I can suggest two options. You can pick whichever one of the two that is most convenient to you:
Use Arduino IDE 1.x
If you want to use the Arduino IDE 1.x tool, you can use Arduino IDE 1.x. The download links for Arduino IDE 1.x are listed here:
You can have both Arduino IDE 2.x and Arduino IDE 1.x installed at the same time on your computer and the two won't cause any problems for each other, so you are welcome to continue using Arduino IDE 2.x as your primary IDE, switching to Arduino IDE 1.x only when you need to upload a SPIFFS filesystem to your ESP32.
Use the command line tools directly
Under the hood, what the "ESP32 sketch data upload" Tool does is:
Generate a SPIFFS filesystem image from the contents of the data subfolder of your sketch.
Upload the filesystem to the ESP32 board.
It does these things using two command line tools:
So instead of using the "ESP32 sketch data upload" Tool from Arduino IDE, you can just work directly with those two tools from the command line terminal.
I wanted to provide an update about this: Uploading filesystems to ESP32 boards using Arduino IDE 2.x is now possible by using the community created "arduino-littlefs-upload" extension: