use Spatie\MediaLibrary\Models\Media;

public function registerMediaConversions(Media $media = null)
{
    $this->addMediaConversion('thumb')
        ->width(130)
        ->height(130);
}

public function registerMediaCollections()
{
    $this->addMediaCollection('main')->singleFile();
    $this->addMediaCollection('my_multi_collection');
}

use Ebess\AdvancedNovaMediaLibrary\Fields\Images;

public function fields(Request $request)
{
    return [
        Images::make('Main image', 'main') // second parameter is the media collection name 
            ->thumbnail('thumb') // conversion used to display the image
            ->rules('required'), // validation rules
    ];
}

use Ebess\AdvancedNovaMediaLibrary\Fields\Images;

    public function fields(Request $request)
    {
        return [
            Images::make('Images', 'my_multi_collection') // second parameter is the media collection name
                ->conversion('medium-size') // conversion used to display the "original" image
                ->thumbnail('thumb') // conversion used to display the image
                ->multiple() // enable upload of multiple images - also ordering
                ->fullSize() // full size column
                ->rules('required', 'size:3') // validation rules for the collection of images
                // validation rules for the collection of images
                ->singleImageRules('dimensions:min_width=100'),
        ];
    }

// Set the filename to the MD5 Hash of original filename
Images::make('Image 1', 'img1')
    ->setFileName(function($originalFilename, $extension, $model){
        return md5($originalFilename) . '.' . $extension;
    });
    
// Set the filename to the model name
Images::make('Image 2', 'img2')
    ->setFileName(function($originalFilename, $extension, $model){
        return str_slug($model->name) . '.' . $extension;
    });