CodeIgniter 4 to access request class for custom library. Maybe there's another nice way, but this is the only way I could think of.

Request.php

<?php
namespace Library\CustomLibrary;
	
use CodeIgniter\HTTP\RequestInterface;

class Request
{
	/**
	 * Instance of the main Request object.
	 *
	 * @var HTTP\IncomingRequest
	 */	
    protected $request;

    public function __construct(RequestInterface $request)
    {
        $this->request = $request;
    }
	
		public function Request()
		{
			return $this->request;
		}
}

class AnotherClass
{
	public function AnotherFunction()
	{
		$request = (new Request)->Request();
		$request->getVar('something');
	}
}