WebPack proxy POST is converted to GET

I have a webpack with proxy as below. All GET requests work OK, but when I try to POST to API I can see in the browser 2 requests. First one seems to be a POST with 301 as status and next one is a GET request. Most probably there are 2 requests because of CORS, but I need both requests to be POST requests not GET.

I need to send data through POST, but webpack seems to change request method to GET.

    proxy: {
        '/api': {
            target: 'http://127.0.0.4/dist',
            secure: false,
            changeOrigin: true,
        }
    },