$documentId = ['iblock','CIBlockDocument',
8481612];
$newStatus = 1; // Замените на ваш новый статус
$runtime = \CBPRuntime::GetRuntime(true);
$runtime->StartRuntime();
$workflow = $runtime->getWorkflow('65eacdce58a5a1.13285138', true);
$a = $workflow->SetWorkflowStatus($newStatus);
$this->GetRootActivity()->SetWorkflowStatus(\CBPWorkflowStatus::Completed);