How to use the webauthn.WebAuthnAssertionOptions function in webauthn

def get_context_data(self, **kwargs):
        ctx = super().get_context_data()
        if 'webauthn_challenge' in self.request.session:
            del self.request.session['webauthn_challenge']
        challenge = generate_challenge(32)
        self.request.session['webauthn_challenge'] = challenge
        devices = [
            device.webauthnuser for device in WebAuthnDevice.objects.filter(confirmed=True, user=self.request.user)
        ] + [
            device.webauthnuser for device in U2FDevice.objects.filter(confirmed=True, user=self.request.user)
        ]
        if devices:
            webauthn_assertion_options = webauthn.WebAuthnAssertionOptions(
                devices,
                challenge
            )
            ad = webauthn_assertion_options.assertion_dict
            ad['extensions'] = {
                'appid': get_u2f_appid(self.request)
            }
            ctx['jsondata'] = json.dumps(ad)
        ctx['form'] = self.form
        return ctx

current_user = admin_users[email]

    challenge = generate_random_string(32)
    session['challenge'] = challenge

    webauthn_user = webauthn.WebAuthnUser(
        current_user['id'],     # user ID
        current_user['email'],  # username
        current_user['email'],  # user display name
        '',  # icon url
        current_user['known_keys'][0]['credential_id'],
        current_user['known_keys'][0]['public_key'],
        current_user['known_keys'][0]['sign_count'],
        RP_ID)

    webauthn_assertion_options = webauthn.WebAuthnAssertionOptions(
        webauthn_user, challenge)

    json_assertion_options = json.dumps(webauthn_assertion_options.assertion_dict)
    # for some reason the allowCredentials ID is a string of bytes.  No bueno for json.dumps


    return render_template('request-security-key.html', assertion_options=json_assertion_options)

def mfaAssert(request):
    if 'mfa_user_id' not in request.session:
        return JsonResponse({'success': False, 'error': _('You need to log in first')})

    if request.user.is_authenticated:
        return JsonResponse({'success': False, 'error': _('You are already logged in')})
    user = get_user_model().objects.get(id=request.session['mfa_user_id'])

    challenge = generate_challenge(32)

    request.session['challenge'] = challenge
    webauthn_users = makeWebauthnUsers(user)

    webauthn_assertion_options = webauthn.WebAuthnAssertionOptions(
        webauthn_users, challenge)

    return JsonResponse(webauthn_assertion_options.assertion_dict)

def get_context_data(self, **kwargs):
        ctx = super().get_context_data()
        if 'webauthn_challenge' in self.request.session:
            del self.request.session['webauthn_challenge']
        challenge = generate_challenge(32)
        self.request.session['webauthn_challenge'] = challenge
        devices = [
            device.webauthnuser for device in WebAuthnDevice.objects.filter(confirmed=True, user=self.user)
        ] + [
            device.webauthnuser for device in U2FDevice.objects.filter(confirmed=True, user=self.user)
        ]
        if devices:
            webauthn_assertion_options = webauthn.WebAuthnAssertionOptions(
                devices,
                challenge
            )
            ad = webauthn_assertion_options.assertion_dict
            ad['extensions'] = {
                'appid': get_u2f_appid(self.request)
            }
            ctx['jsondata'] = json.dumps(ad)
        return ctx