$clone = $model->load({Связи для дублирования})->replicate();
$clone->push();

foreach ($clone->getRelations() as $relationName => $relationValue){
    if (empty($relationValue)) {
        continue;
    }

    if ($relationValue instanceof \Illuminate\Database\Eloquent\Collection) {
    $clone->{$relationName}()->sync($relationValue->all());
    }
    
    if ($relationValue instanceof \Illuminate\Database\Eloquent\Model) {
        $clone->{$relationName}()->add($relationValue);
    }
}