Request.redirect could be "follow"
, "error"
or "manual"
.
If it is “follow”, fetch() API follows the redirect response (HTTP
status code = 301,302,303,307,308).If it is “error”, fetch() API treats the redirect response as an
error.If it is “manual”, fetch() API doesn’t follow the redirect and returns
an opaque-redirect filtered response which wraps the redirect
response.
Since you want to redirect after a fetch just use it as
fetch(url, { method: 'POST', redirect: 'follow'})
.then(response => {
// HTTP 301 response
})
.catch(function(err) {
console.info(err + " url: " + url);
});