Require a class from another class - php

I'm learning PHP. And I have a problem that I can't understand. This my situation:

I have a directory called Lib. This is the structure of my directory:

In the directory database I wrote a class QueryBuilder.

<?php

//require '../Task';

class QueryBuilder{

    public function selectAll($table,$pdo){

        $statement = $pdo->prepare("Select * from {$table}");

        $statement->execute();

        return $statement->fetchAll(PDO::FETCH_CLASS,'Task');
    }
}
?>

In the class I use an external class Task that I wrote before and that I use in the statement return.

return $statement->fetchAll(PDO::FETCH_CLASS,'Task');

This is the Task class:

<?php

    class Task{
        
        protected $description;
        protected $completed=false;
    
        public function __contruct($description){
    
            $this->description = $description;
    
        }
    
    
        public function getDescription(){
    
            return $this->description;
    
        }
    
    
        public function getCompleted(){
    
            return $this->completed;
        }
    
    }
    
    
    ?>

So I thought that If I wanted to use the Task class I had to import the file. So at the beginning of the my class QueryBuilder I wrote the require statement.

require '../Task';

The problem is that when I run my class I get this error:

Warning: require(../Task): failed to open stream: No such file or directory in C:\Users\Administrator\OneDrive - Sogei\Desktop\php-learning\php-course\Lib\database\QueryBuilder.php on line 3

Fatal error: require(): Failed opening required '../Task' (include_path='C:\xampp\php\PEAR') in C:\Users\Administrator\OneDrive - Sogei\Desktop\php-learning\php-course\Lib\database\QueryBuilder.php on line 3

Without the require statement instead the class works.

How is it possible? Is not necessary import the Task class?