Route::prefix('auction')->namespace('Auction')->name('auction.')->group(function() {
    Route::get('delegations/{auction}/view/{lot}', 'AuctionDelegatorsController@delegation')->name('delegations');

@slot('url') {{route('auction.delegations', $auction, $lot)}} @endslot

Missing required parameters for [Route: auction.delegations] [URI: auction/delegations/{auction}/view/{lot}]

{{route('auction.delegations',['auction'=> $auction,'lot' => $lot])}}