Redirecting backend calls in Vue application

I am trying to deploy my website written in Vue to a static webhosting service (AWS S3).

I have been using the bencodezen boilerplate which seems to be generated using Vue-CLI. The boilerplate comes with a pre-configured development server such that you can redirect the backend calls (using axios) to either a mock backend or to a production backend:

vue.config.js

module.exports = {
    [...]
    // Configure Webpack's dev server.
    // https://cli.vuejs.org/guide/cli-service.html
    devServer: {
    ...(process.env.API_BASE_URL
      ? // Proxy API endpoints to the production base URL.
        { proxy: { '/api': { target: process.env.API_BASE_URL } } }
      : // Proxy API endpoints a local mock API.
        { before: require('./tests/mock-api') }),
    },
}

All calls to myurl.com/api/* will be directed to either the mocked backend or the API_BASE_URL if such is defined. This works fine while using the vue-cli-service serve development server but I’m failing to understand how to translate this to AWS S3, or any other webserver suited for production. If I try to make a login, post-request I get the following response from AWS:

405 Method Not Allowed

Indicating that the call was never redirected (AWS S3 doesn’t allow POST calls).

Is it possible to redirect the API-calls directly from the web browser to the backend without going through the webserver? If not, how to I setup my production webserver in such a ways that the calls to myurl.com/api/* are automatically forwarded?