Cannot read properties of undefined (reading ‘forEach’) when no Array

I got this error :

Cannot read properties of undefined (reading ‘forEach’)

if(response.Response) {
      $('#list').html('');
      response.Search.forEach(function(movie) {        
        var movieContent;
        if(movie.Poster === 'N/A') {
          movieContent = `<li class="list-group-item">${movie.Title} - ${movie.Year}</li>`;
        } else {
          movieContent = `<li class="list-group-item">${movie.Title} - ${movie.Year} <a href="${movie.Poster}" class="btn btn-xs btn-primary" id="poster-link">Poster</a></li>`;
        }
        $('#list').append(movieContent).hide().fadeIn(); 
      });
    }
  });

The error comes when I put less than 3 letters in my search input and the output is

{Response: ‘False’, Error: ‘Too many results.’}

otherwise, from 3 letters the response is correct

{Search: Array(2), totalResults: ‘2’, Response: ‘True’}

I understand that this is because there is no Array in the response but how can I prevent this error?