Good morning. The project I'm working with was written for Arduino, so I had to get everything declared. I did that already. But now there's a JSON hangup. The program uses this:

StaticJsonDocument<6000> doc;

The 'doc' isn't declared anywhere, but it shows up a lot in the program.
Can anybody help me get past this? I think this would eliminate the last errors.
Code:
~~~

include <Arduino.h>

include <Wire.h>

include <TFT\_eSPI.h>

include <WiFiUdp.h>

include <HTTPClient.h>

include <ArduinoJson.h>

include "Splash.h"

include <NTPClient.h>

include <WiFiUdp.h>

include <HTTPClient.h>

include "Wifi_Icons.h"

//#include <Adafruit\_NeoPixel.h>

TFT_eSPI tft = TFT_eSPI();

WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP, "pool.ntp.org");
String months[12] = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};

uint32_t targetTime = 0;
const long interval = 60000; // Update every minute

const char *ssid = "SSID";
const char *password = "PASSWORD";

define LCD_BACKLIGHT 21

define TFT_LIGHTGREY 0xD69A

define TFT_DARKGREY 0x4208

define TFT_GREEN 0x07E0

define TFT_LightBlue 0x867D

define TFT_Orange 0xFDA0

define TFT_SILVER 0xC618

define TFT_PURPLE 0x780F

String payload = "";
double current = 0;

unsigned long previousTime = 0;
const unsigned long eventInterval = 300000; // 300000 is 5 minutes
// const unsigned long eventInterval=600000;   //600000 is 10 minutes

StaticJsonDocument<6000> doc;

// int deb=0;
// int brightnes[5]={40,80,120,160,200};
// int b=1;
void connect_to_wifi()
{
  WiFi.begin(ssid, password);
  tft.setTextColor(TFT_GREEN, TFT_BLACK);
  tft.setTextSize(2);
  tft.setCursor(45, 100);
  tft.print("Connecting to Wifi");
  delay(2000);

  while (WiFi.status() != WL_CONNECTED)
  {
delay(150);
tft.print(".");
delay(150);
  }
  tft.fillScreen(TFT_BLACK);
  tft.setTextSize(2);
  tft.setCursor(90, 100);
  tft.print("Connected");
  tft.setCursor(95, 130);
  tft.print("IP address: ");
  tft.setCursor(90, 160);
  tft.print(WiFi.localIP());
  delay(4000);
  tft.fillScreen(TFT_BLACK);
}

void main_page()
{
  tft.setTextSize(1);
  tft.setTextColor(TFT_LightBlue, TFT_BLACK);
  tft.drawString("Symbol", 28, 0, 2);
  tft.drawString("Price", 125, 0, 2);
  tft.drawString("Gains/Losses", 193, 0, 2);

  tft.drawLine(20, 20, 290, 20, TFT_WHITE);
  tft.drawRoundRect(18, 163, 280, 77, 6, TFT_WHITE);
}

void read_price(int x_i, int y_i, String stock_name)
{
  float currentPrice;
  float differenceInPrice;
  float percentchange;

  HTTPClient http;
  http.begin("https://finnhub.io/api/v1/quote?symbol=" + stock_name + "&token=YOUR-TOKEN-HERE"); // Edit your key here

  int httpCode = http.GET();
  if (httpCode > 0)
  {
payload = http.getString();
char inp[payload.length()];
payload.toCharArray(inp, payload.length());
deserializeJson(doc, inp);

// c = Current price, d = Change, dp = Percent change, pc = Previous close price
String v = doc["c"];
String c = doc["dp"];
current = v.toDouble();
percentchange = c.toDouble();

tft.setTextSize(1);
tft.setTextColor(TFT_Orange, TFT_BLACK);
tft.drawString(stock_name, x_i, y_i, 2);
tft.setTextColor(TFT_LIGHTGREY, TFT_BLACK);
tft.drawString(" ", 50 + x_i, y_i, 2);
tft.drawString(String(current), 85 + x_i, y_i, 2);

if (percentchange < 0.0)
{
tft.setTextColor(TFT_RED);
tft.drawString(" ", 130 + x_i, y_i, 2);
tft.drawString(String(percentchange), 165 + x_i, y_i, 2);
tft.drawString("  %", 195 + x_i, y_i, 2);
}

else
{
tft.setTextColor(TFT_GREEN);
tft.drawString(" ", 130 + x_i, y_i, 2);
tft.drawString(String(percentchange), 170 + x_i, y_i, 2);
tft.drawString(" %", 200 + x_i, y_i, 2);
}
  }
}

void stock_page(String s1, String s2, String s3, String s4, String s5, String s6, String s7, String s8, String s9)
{
  read_price(40, 23, s1);
  read_price(40, 38, s2);
  read_price(40, 53, s3);
  read_price(40, 68, s4);
  read_price(40, 83, s5);
  read_price(40, 98, s6);
  read_price(40, 113, s7);
  read_price(40, 128, s8);
  read_price(40, 143, s9);
}

void show_RSSI()
{
  tft.drawString(String(WiFi.RSSI()), 242, 168, 2);
  tft.drawString("dBm", 265, 168, 2);
}

void reset_screen()
{
  tft.fillScreen(TFT_BLACK);
}

void setup()
{
  Serial.begin(115200);
  tft.init();
  Wire.begin(13, 4); // Pico mini
  tft.setRotation(1);
  tft.setSwapBytes(true);
  tft.fillScreen(TFT_BLACK);
  pinMode(LCD_BACKLIGHT, OUTPUT);

  WiFi.mode(WIFI_AP_STA);

  // Set device as a Wi-Fi Station
  WiFi.begin(ssid, password);
  connect_to_wifi();

uint16_t error;
  char errorMessage[256];

  tft.setRotation(1);
  tft.pushImage(0, 0, 320, 240, Splash);
  delay(3000);
  reset_screen();

  main_page();
  show_RSSI();
  stock_page("ASTI", "NVDA", "NVDY", "ADM", "ADMY", "MSTY", "ULTY", "CONY", "GOEV"); // Edit your preferred stocks here

  timeClient.begin();
  timeClient.setTimeOffset(-10800); // My timezone
}

void loop()
{
  unsigned long currentTime = millis();
  timeClient.update();

  time_t epochTime = timeClient.getEpochTime();
  struct tm *ptm = gmtime((time_t *)&epochTime); // Get a time structure

  int monthDay = ptm->tm_mday;
  int currentMonth = ptm->tm_mon + 1;
  String currentMonthName = months[currentMonth - 1];
  int currentYear = ptm->tm_year + 1900;
  String currentDate = String(currentYear) + "-" + String(currentMonth) + "-" + String(monthDay);

  tft.drawLine(30, 187, 280, 187, TFT_WHITE);

  tft.setTextColor(TFT_LightBlue, TFT_BLACK);
  tft.drawString(String(currentDate), 30, 168, 2);
  tft.drawString(String(timeClient.getFormattedTime()), 175, 168, 2);

  digitalWrite(LCD_BACKLIGHT, HIGH);
  Serial.println("Waiting...");
  delay(100);
  main_page();

  if (currentTime - previousTime >= eventInterval)
  {
Serial.println("Refresh Data");
reset_screen();
stock_page("BTC", "ETH", "AAPL", "NVDA", "MSFT", "SPOT", "AMZN", "BAC", "TSLA"); // Edit your stock names here
previousTime = currentTime;
timeClient.update();
  }
}

'''