How to capture PHP errors, functions or methods using Monolog?

Question

Good afternoon, I’m trying to create error checker, for whenever you have any particular PHP error on client side send register a Log.

My problem is this, how can I capture PHP errors to upload to this log? I can already send the message and even send information from the server however, due to the lack of information on the internet, I could not understand how I can call this file in my pages to always run and take these parts that gave errors and pass to the message I want to send in PHP.

<?php 
use Monolog\Handler\BrowserConsoleHandler;
use Monolog\Handler\StreamHandler;
use Monolog\Handler\SendGridHandler;
use Monolog\Handler\TelegramBotHandler;
use Monolog\Formatter\LineFormatter;
use Monolog\Logger;
use Monolog\Processor\IntrospectionProcessor;
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\SMTP;
use PHPMailer\PHPMailer\Exception;
use Monolog\ErrorHandler;

require __DIR__."/vendor/autoload.php";

$logger = new Logger("CONNECT");
$logger->pushHandler(new BrowserConsoleHandler(Logger::DEBUG));
$logger->pushHandler(new StreamHandler(__DIR__."/log.txt",Logger::WARNING));
$logger->pushHandler(new StreamHandler("php://output", Logger::ERROR));
$logger->pushProcessor(new IntrospectionProcessor(Logger::DEBUG));
$logger->pushProcessor(function($record){
    $record["extra"]["SCRIPT_NAME"] = $_SERVER["SCRIPT_NAME"];
    });
$logger->pushProcessor(new IntrospectionProcessor(Logger::DEBUG));

//TELEGRAM
$tele_key = "meuapiid";
$tele_channel = "meapikey";
$tele_handler = new TelegramBotHandler($tele_key, $tele_channel,Logger::EMERGENCY);
$tele_handler->setFormatter(new LineFormatter("%level_name%\n %channel% \n [%datetime%]  \n%context% \n %message% \n %extra%"));
$logger->pushHandler($tele_handler);

$logger->debug("Erro encontrado!");
$logger->info("Erro encontrado!");
$logger->notice("Erro encontrado!");
$logger->warning("Erro encontrado!");
$logger->error("Erro encontrado!");
$logger->critical("Erro encontrado!");
$logger->alert("Erro encontrado!");
$logger->emergency("Erro encontrado!");