Пишу по уроку код, как исправить эту ошибку? Uncaught (in promise)

Question

Пишу по уроку код, как исправить эту ошибку? Uncaught (in promise)

TypeError: states.filter is not a function
at searchStates

const search = document.getElementById("inp");
const matchList = document.getElementById("match-list");

// Search json and filter it
const searchStates = async searchText => {
const res = await fetch('macro_data/');
const states = await res.json();

// Get matches to current text input
let matches = states.filter(state => {
const regex = new RegExp(`^${searchText}`, 'gi');
return state.title
});
console.log(matches);
};

search.addEventListener('input', () => searchStates(search.value));