Why is the line 7 is always error what's wrong?

#include <SPI.h> #include <Wire.h> #include <Adafruit_SSD1306.h> #include <nRF24L01.h> #include <RF24.h> // === OLED Display === #define SCREEN_WIDTH 128 #define SCREEN_HEIGHT 64 Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1); // === RF24 Setup === RF24 radio(9, 10); // CE, CSN pins for nRF24L01 const byte address[6] = "RTR01"; // Unique RF channel for the team // === MAC Address for this unit === const char* DEVICE_MAC = "D1:02:B7:A4:C3:9E"; // === Pins === #define PTT_BUTTON_PIN 4 #define TEXT_BUTTON_PIN 5 #define PANIC_BUTTON_PIN 6 #define VIBRATION_PIN 3 // === Timing === unsigned long lastPingTime = 0; unsigned long timeoutInterval = 5000; // 5 seconds timeout to trigger vibration // === RF Payload Structure === struct RFMessage { char mac[18]; char message[32]; bool panic; }; // === Payload Buffer === RFMessage outgoing; // === Setup === void setup() { Serial.begin(9600); pinMode(PTT_BUTTON_PIN, INPUT_PULLUP); pinMode(TEXT_BUTTON_PIN, INPUT_PULLUP); pinMode