CURL *hnd = curl_easy_init();

curl_easy_setopt(hnd, CURLOPT_CUSTOMREQUEST, "GET");
curl_easy_setopt(hnd, CURLOPT_URL, "https://text-to-speech27.p.rapidapi.com/speech?text=xin%20ch%C3%A0o%20vi%E1%BB%87t%20nam&lang=vi");

struct curl_slist *headers = NULL;
headers = curl_slist_append(headers, "X-RapidAPI-Key: bb5c73ea34mshf3bfc93e2a6897dp1ed8d3jsn7c018dc9627d");
headers = curl_slist_append(headers, "X-RapidAPI-Host: text-to-speech27.p.rapidapi.com");
curl_easy_setopt(hnd, CURLOPT_HTTPHEADER, headers);

CURLcode ret = curl_easy_perform(hnd);