This is error message -> WordsApi

message-> Fatal error : Uncaught Error: Class “SplitDocumentOnlineRequest” not found

source->

use Aspose\Words\WordsApi;

$wordsApi = new WordsApi('-347', 0000');


$doc = "Input.html";
$request = new SplitDocumentOnlineRequest(
    $doc, "jpg", NULL, NULL, NULL, NULL, NULL, NULL, true, NULL
);  ->error point.

$split = $wordsApi->splitDocumentOnline($request);

Please check this examples

I think you probably miss using SplitDocumentOnlineRequest