Pass data to django framework using javascript (no jquery)

I have a dropdown list that I got from an uploaded CSV file from Django that I want to pass back to a different Django view with javascript when selected. I keep getting a 404 error (index.js:9 POST http://127.0.0.1:8000/gui_app/%7B%%20url%20%22get_selection%22%20%%7D 404 (Not Found) (anonymous) @ index.js:9 ) when I click on the select button after I choose a value from the dropdown. From what I understand reading the error message, the issue seems to be coming from javascript not being able to render the url the correct way. What’s the correct way to pass the url in javascript so that javascript recognizes it and passes the data to the view? Here’s my code below

index.js

let signalSelectButton = document.getElementById("signalSelectButton")
const url = loacation.href('/get_selection/')

signalSelectButton.addEventListener("click", function() {
  console.log("clicked")
  const selectedValue = document.getElementById("signalSelect").value
  console.log(selectedValue)
  
  fetch(url, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'X-CSRFToken': '{{ csrf_token }}'
    },
    body: JSON.stringify({selected_value: selectedValue})
    })
    .then(response => {
      if (!response.ok) {
        throw new Error('Network response was not ok')
      }
      return response.json()
    })
    .then(data => {
      console.log(data)
      document.getElementById('response-message').innerText = data.message
  })
    .catch(error => {console.error('Error:', error)})
})

views.py

from django.shortcuts import render, redirect
from django.http import HttpResponse, HttpResponseRedirect, JsonResponse
from django.conf import settings
from django.core.files.storage import FileSystemStorage
from .forms import SigFileForm
from django.contrib import messages
from django.views.decorators.csrf import csrf_exempt
import os
import pandas as pd

# Create your views here.
def index(request):
    return HttpResponse("Hello, world!")
        
def model_upload(request):
    # return render(request, 'model_upload.html')
    if request.method == 'POST':
        form = SigFileForm(request.POST, request.FILES)
        if form.is_valid():
            sigfile = request.FILES['file']
            sigfile_name = sigfile.name
            sigfile_size = sigfile.size
            instance = form.save()
            sigfile_url = instance.file.url
            choices = populate_dropdown(sigfile_url)
            messages.success(request, 'File uploaded successfully!')
            return render(request, 'model_upload.html', {'form': form, 'choices': choices})
        else:
            return render(request, 'model_upload.html', {'form': form})
    else:
        form = SigFileForm()
        return render(request, 'model_upload.html', {'form': form})
        
def populate_dropdown(file_url):
    file_path = os.path.join(settings.MEDIA_ROOT, file_url.lstrip('/media/'))
    if os.path.exists(file_path):
        df = pd.read_csv(file_path, sep = ',', index_col = 'Time,ms')
        choices =  df.columns.values.tolist()
        return choices
    else:
        print(f'File does not exist: {file_path}')
        return []
        
@csrf_exempt
def get_selection(request):
    if request.method == 'POST':
        selected_value = request.POST.get('selected_value')
        return JsonResponse({'message': f'You selected: {selected_value}'})
    else:
        return JsonResponse({'message': ''})

urls.py

from django.urls import path

from . import views

urlpatterns = [
    path("", views.index, name = "index"),
    path("simple_upload", views.simple_upload, name = "simple_upload"),
    path("model_upload", views.model_upload, name = "model_upload"),
    path("get_selection", views.get_selection, name = "get_selection"),
]