Want to add in in Laravel

I want to set in

This is my code:

@foreach($details as $value)
    <a href=""> </a>
@endforeach

Controller function:

public function viewhome(Request $req){
    $product = product::all()->unique('category');
    return view('homepage',['details'=> $product]);}

Route:

Route::get('/homepage/db_val', 'HomeController@db_val')->name('db_val');

How to declare href properly. And what will be the route. Thank you.

via Chebli Mohamed