Send a curl request with no Accept header?

$api_url = 'https://api.fax.ir/v1/accounts/selfe';
$accessToken = get_option('faxir_access_token');
$ch = curl_init($api_url);
curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)");
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
    'Authorization: Bearer '.$accessToken,
    'x-faxir-clientid: '.$this->client_id
));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch,CURLOPT_VERBOSE,1);
$output = curl_exec($ch);
echo "Code:".curl_getinfo($ch, CURLINFO_HTTP_CODE)."<br>";
echo "Error Number:".curl_errno($ch)."<br>";
echo "Error String:".curl_error($ch);
curl_close($ch);
echo $output;