What to use instead of SPIFFS on aduino uno wifi rev 2?

Hello!

I am working on a project were I am trying to use the arduino to serve a webpage to show some graphs of an incoming stream of data. To create the graphs i got inspiration from a tutorial I found where they used the ESP32/ESP8622. They created the graphs in a HTML file and then used that to show it on the server. They used a function called SPIFFS and I understood that is something for the ESP wifi modules but is there something like that I can use on my arduino uno wifi rev 2?

Here is the tutorial I found: ESP32/ESP8266 Plot Sensor Readings in Real Time Charts | Random Nerd Tutorials

More specific it is about these lines of code:
// Initialize SPIFFS
if(!SPIFFS.begin()){
Serial.println("An Error has occurred while mounting SPIFFS");
return;
}
// Route for root / web page
server.on("/", HTTP_GET, (AsyncWebServerRequest *request){
request->send(SPIFFS, "/index.html");
});
server.on("/temperature", HTTP_GET, (AsyncWebServerRequest *request){
request->send_P(200, "text/plain", readBME280Temperature().c_str());
});
server.on("/humidity", HTTP_GET, (AsyncWebServerRequest *request){
request->send_P(200, "text/plain", readBME280Humidity().c_str());
});
server.on("/pressure", HTTP_GET, (AsyncWebServerRequest *request){
request->send_P(200, "text/plain", readBME280Pressure().c_str());
});

I have worked with arduino before but never with web servers. Thank you in advance!!

SPIFFS is the Flash File System availabler over SPI of the ESP32:

SPIFFS_Test.ino

The Uno WiFi Rev 2 seems to have only EEPROM attached, but this is not a good idea for storing data of a HTML page. Have you tried to use PROGMEM? But this migh increase the size of the image in a way that it would fit, because the overall flash memory is about 48KB where already a noticable portion would be used by the bootloader. So you may can only use some KB for the HTML pages.