audio cannot played but detected to local storage

Using Django
1

my website have form using models to upload audio file. when it uploaded, the file cannot be played but at my terminal it’s already detected the file name. but when i open new page, the audio can be play without i need to upload again. anyone know what’s wrong?
here’s my html:

<audio controls="controls">
     <source src="/media/mp3/{{last_audio.audio}}" type="audio/mpeg">
</audio>

views.py:

def homepage(request):
    form = AudioForm()
    last_audio = Audio_store.objects.all().last()
    if request.method == "POST":
        form = AudioForm(request.POST, request.FILES)
        if form.is_valid():
            
            audio = form.cleaned_data.get("audio")
            print(audio)
            context={'form':form, 'last_audio':audio}
            print(context)
            form.save()
            return render(request, "homepage.html", context=context)

    context={'form':form, 'last_audio':last_audio}
    return render(request, "homepage.html", context=context)

models.py:

from django.db import models
from django.core.files.storage import FileSystemStorage

fs = FileSystemStorage(location='media/mp3')
fss = FileSystemStorage(location='media/txt')

class Audio_store(models.Model):
    password=models.FileField(storage=fss, null=True)
    audio=models.FileField(storage=fs, null=True)