Implementing pause resume timer

I am facing issues in creating a pause and resumable timer. I have pauseResume function to pause the execution of the code when I give certain input from keyboard and resume when I take another input from the keyboard. The timer has to run continuously until I pause it. It is not working, can someone help me with this? How do I take input and control the loop?

#include <iomanip>
#include <iostream>
#include <stdlib.h>
#include <unistd.h>
#include <thread>
#include <chrono>

using namespace std;
using std::copy;
using std::this_thread::sleep_for;
using namespace std::chrono_literals;

// hours, minutes, seconds of timer
int hours = 0;
int minutes = 0;
int seconds = 0;

int pauseResume()
{
    int flag;
    cout << "Program is paused !" << std::endl
         << "Press Enter to continue" << std::endl;

    // pause the program until user input
    flag = getc(stdin);

    cout << "\nContinuing .";
    sleep_for(300ms);
    cout << "...";
    cout << "\nProgram finished with success code!" << std::endl;

    return EXIT_SUCCESS;
}

// function to display the timer
void displayClock()
{
    // system call to clear the screen
    system("clear");

    cout << setfill(' ') << setw(55) << "         TIMER         \n";
    cout << setfill(' ') << setw(55) << " --------------------------\n";
    cout << setfill(' ') << setw(29);
    cout << "| " << setfill('0') << setw(2) << hours << " hrs | ";
    cout << setfill('0') << setw(2) << minutes << " min | ";
    cout << setfill('0') << setw(2) << seconds << " sec |" << endl;
    cout << setfill(' ') << setw(55) << " --------------------------\n";
}

void timer()
{
    // char operation;
    // std::cout << "Enter operation: ";
    // std::cin >> operation;

    // if(operation =='p')
    // // {
    // do
    // {

    // bool startTimer = true;
    // bool pauseTimer = false;

    while (true)
    // while()
    {
        // display the timer
        displayClock();

        // sleep system call to sleep for 1 second
        sleep(1);

        // increment seconds
        seconds++;

        if (seconds == 10)
        {
            // // increment minutes
            // minutes++;

            // // if minutes reaches 60
            // if (minutes == 60)
            // {
            //     // increment hours
            //     hours++;
            //     minutes = 0;
            // }
            // seconds = 0;

            break;
        }
        // char pausePlay;
        // std::cout << "Enter p to pause";
        // std::cin >> pausePlay;

        // if(pausePlay == 'p')
        // {
        //     pauseResume();
        // }
    }
    char pausePlay;
    std::cin >> pausePlay;

    if (pausePlay == 'p')
    {
        pauseResume();
    }
    // }while(operation != 'e');
}
// }

// Driver Code
int main()
{
    // start timer from 00:00:00
    timer();
    return 0;
}