how to redirect to another controller after post request succeed via stimulus

Question

So i create a shortener url web application using Ruby on Rails with stimulus.

So when it goes to localhost:3000 it will goes to root url which will be handled by home_controller.rb method index and the view is like this below

<div class="px-4 py-5 my-5 text-center">
  <%=image_tag("logo.svg", class: "d-block mx-auto mb-4", height: '57', width: '72')%>
  <h1 class="display-5 fw-bold">MINIURL</h1>
  <div class="col-lg-6 mx-auto">
    <p class="lead mb-4">Your Alternative URL Shortener</p>
    <div data-controller="home">
      <div class="input-group mb-3">
        <input type="text" class="form-control" placeholder="Place URL here" id="url-query" data-home-target="urlquery">
        <button class="btn btn-primary" type="button" id="button-shorten" data-action="click->home#shorten">Shorten!</button>
      </div>
    </div>
  </div>
</div>

it connect to home_controller.js

import { Controller } from "@hotwired/stimulus"
import { FetchRequest } from '@rails/request.js'

export default class extends Controller {
  static targets = [ "urlquery" ]

  connect(){
    console.log("home controller connected!")
  }

  shorten(){
    const urlQueryElement = this.urlqueryTarget
    const urlQuery = urlQueryElement.value
    const requestData = { og_url: urlQuery }

    this.postShorten(requestData)
  }

  async postShorten (bodyRequest) {
    try {
      const request = new FetchRequest(
        'post', '/mappings',
        { body: JSON.stringify(bodyRequest) }
      )
      await request.perform()
    } catch (error) {
      return error
    }
  }
}

what it does basically just send url from the input text to rails controller which is at /mappings via POST method.

Everything went well. data got saved. the POST request goes to mappings_controller.rb method create, this is my code

def create
    original_url = mappings_param[:og_url]
    rand_key = SecureRandom.alphanumeric(8)

    mapping_url = Mapping.new(
      og_url: original_url,
      key: rand_key,
      hit_count: 0
    )

    if mapping_url.valid?
      # mapping_url.save!
      render template: "mappings/show"
      return
      # render :json => {:short_url => "#{request.host}/#{mapping_url.key}"}
      # redirect_to action: :show, id: "#{request.host}/#{mapping_url.key}"
      # redirect_to root_path(:short_url => "#{request.host}/#{mapping_url.key}")
      # respond_to do |format|
      #   format.js   { render :js => "window.location='#{ root_path }'" , :locals => {:short_url => "#{request.host}/#{mapping_url.key}"}}
      # end
      # respond_to do |format|
      #   format.turbo_stream { redirect_to root_path(:short_url => "#{request.host}/#{mapping_url.key}") }
      # end
    else
      head :bad_request
    end
  end

I want it to be redirect to root_path but with parameter shortened url. but it won't redirect. i already try several codes (you can see by code that i comment out). instead it just show text/html response if i see via console.

how can i redirect to root path with parameter after request post succeed and i want to put the shortened url in the input form. thanks