How do I know if the pagination was clicked in the Readable?

Question

I have a problem sending a parameter from one view to another. Until then beauty is working, but I’m having problems in paging, because it gives error in this parameter I need to send, to solve this need to leave this parameter nulo, but for that would have to check if page was clicked. You have to know that?

Follows the controller method:

public function index(Request $request)
{     
    $search = $request->get('search');
    $btn = $request->query();

    $products = DB::table('products')->when($search , function ($query) use ($search ) {
                    return $query->where('name', 'like', '%'. $search .'%' )
                            ->orWhere('detalhe', 'like', '%'. $search .'%')
                            ->orWhere('id', 'like', '%'.$search.'%');
                })->paginate(5);


    return view('products.index', compact('products','btn'))
            ->with('i', (request()->input('page', 1) -1)* 5);

    //dd($btn);
//        $products = Product::latest()->paginate(5);
//        
//        return view('products.index', compact('products','btn'))
//                ->with('i', (request()->input('page', 1) -1)* 5);
}

one thing that could serve is to capture the current page, someone knows how to do this?