arduino download to SPIFFS

#include "Arduino.h"
#include "WiFi.h"
#include "SPIFFS.h"
#include "HTTPClient.h"

HTTPClient http;
uint8_t buffer[8192];
constexpr static const char* url = "http://192.168.54.12/test.bin";
void setup() {
    Serial.begin(115200);
    char ssid[65];
    ssid[0] = 0;
    char pass[129];
    pass[0] = 0;
    SPIFFS.begin();
    // check SPIFFS for /wifi.txt.
    // first line is ssid, second line is password
    bool loaded = false;
    puts("Looking for wifi.txt creds on internal flash");
    if (SPIFFS.exists("/wifi.txt")) {
        File file = SPIFFS.open("/wifi.txt", "r");
        // parse the file
        String str = file.readStringUntil('\n');
        if (str.endsWith("\r")) {
            str = str.substring(0, str.length() - 1);
        }
        strncpy(ssid, str.c_str(), sizeof(ssid));
        str = file.readStringUntil('\n');
        file.close();
        if (str.endsWith("\r")) {
            str = str.substring(0, str.length() - 1);
        }
        strncpy(pass, str.c_str(), sizeof(pass));
        loaded = true;
    }
    WiFi.mode(WIFI_STA);
    WiFi.disconnect();
    // if we found wifi.txt, start the connection process:
    if (loaded) {
        printf("Read wifi.txt. Connecting to %s\n", ssid);
        WiFi.begin(ssid, pass);
    } else {
        puts("wifi.txt not found - using remembered creds");
        WiFi.begin();
    }
    // there are more steps to using https, not covered here
    if(http.begin(url)) {
        File dst = SPIFFS.open("/test.bin","wb",true);
        NetworkClient src = http.getStream();
        while(1) {
            size_t bytes_read = src.readBytes(buffer,sizeof(buffer));
            if(bytes_read==0) {
                break;
            }
            dst.write(buffer,bytes_read);
        }
        dst.close();
    }
    http.end();

}
void loop() {

}