#include "SPIFFS.h"#include "Update.h" void setup() {    Serial.begin(115200);    if(!SPIFFS.begin(true)){        Serial.println("An Error has occurred while mounting SPIFFS");        return;   }      File file = SPIFFS.open("/firmware.bin");     if(!file){        Serial.println("Failed to open file for reading");        return;    }          Serial.println("Starting update..");           size_t fileSize = file.size();    if(!Update.begin(fileSize)){             Serial.println("Cannot do the update");       return;    };    Update.writeStream(file);    if(Update.end()){            Serial.println("Successful update");      }else {            Serial.println("Error Occurred: " + String(Update.getError()));      return;    }        file.close();    Serial.println("Reset in 4 seconds...");    delay(4000);    ESP.restart();} void loop() {}Source: ESP32 Arduino: Updating firmware from the SPIFFS file system – techtutorialsx
ESP32 Arduino: Updating firmware from the SPIFFS file system was last modified:  January 2nd, 2022 by