var params = new URLSearchParams(window.location.search); var id = params.get('id'); fetch(api+'/client', { method: 'POST', body: JSON.stringify({ client_id : id }) }).then(handleResponse); async function handleResponse(response){ if (response.ok){ var json = await response.json(); get('client_id').value = json.client_id; get('name').value = json.name; get('secret').value = json.secret; get('redirects').value = json.redirect_uris.join("\n"); } }