Images not generated when used in CSS

Is the problem happening because the image URL is missing the "itok" security token, thus the system blocks generation of the new image variation? This seems more like a core issue than something specific to Focal Point.

Hi, I have generated image style with focal point programatically by passing static x and y coordinate.
Please use file_url_generator service instead of file_url_transform_relative(),

namespace Drupal\custom_image_style\Service;

use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\media\MediaInterface;
use Drupal\Core\File\FileUrlGeneratorInterface;

class ImageStyleService {

  protected $entityTypeManager;
  protected $fileUrlGenerator;

  public function __construct(EntityTypeManagerInterface $entityTypeManager, FileUrlGeneratorInterface $fileUrlGenerator) {
    $this->entityTypeManager = $entityTypeManager;
    $this->fileUrlGenerator = $fileUrlGenerator;
  }

  /**
   * Code to get file path.
   */
  public function getFilePath(MediaInterface $entity, string $image_style) {
    $fid = $entity->getSource()->getSourceFieldValue($entity);
    /** @var \Drupal\file\FileInterface $file */
    $file = $this->entityTypeManager->getStorage('file')->load($fid);

    //Add crop type and focal point
    $focal_point_manager = \Drupal::service('focal_point.manager');
    $crop = $focal_point_manager->getCropEntity($file, 'focal_point');

    $width = 300;
    $height = 200;
    $focal_point = "9,20";
    if ($focal_point && $width && $height) {
        [$x, $y] = explode(',', $focal_point);
        $focal_point_manager->saveCropEntity($x, $y, $width, $height, $crop);
    }

    /** @var \Drupal\image\ImageStyleInterface $style */
    $style = $this->entityTypeManager->getStorage('image_style')->load($image_style);
    $file_path = $style->buildUrl($file->getFileUri());

    return $file_path;
  }

  /**
   * Code to create CSS.
   */
  public function generateStyles(string $selector, string $file_path) {
    // Use file_url_generator to transform the file URL to relative.
    $relative_url = $this->fileUrlGenerator->transformRelative($file_path);

    $css = sprintf('%s {', $selector);
    $css .= sprintf('background-image: url(\'%s\');', $relative_url);
    $css .= '}';

    return $css;
  }

}