Why can't the generated image (Captcha) be displayed?

Question

PHP

A simple, notorious captcha was written for the Site , just to be. The problem is that on the local - it all works fine, but as soon as it is transferred to the hosting - it stops working. If you run this file manually, it will display an error referring to line 11, that is, to this one:

imageTtfText($im, 28, -25, 30, 25, $c, __DIR__."/fonts/18928.ttf", $rand);

Captcha code:

<?php
    session_start();
    $rand = mt_rand(1000000, 9999999);

    $_SESSION["rand"] = $rand;
 
    $im = imageCreateTrueColor(250,90,);
 
    $c = imageColorAllocate($im, 55, 55, 55);
 
    imageTtfText($im, 28, -25, 30, 25, $c, __DIR__."/fonts/18928.ttf", $rand);
 
    header("Content-type: image/png");
 
    imagePng($im);
 
    imageDestroy($im);
?>

How it looks on local:

And already in public access: