django problem email verification keeps failing

I have been using django for some year now but not as always
what would probably be the issue to the email verification keeps failing sometimes.
here are the code i wrote

from django.contrib.auth.tokens import PasswordResetTokenGenerator

class TokenGenerator(PasswordResetTokenGenerator):
 def _make_hash_value(self, user, timestamp):
    return (
    str(user.pk) + str(timestamp) + str(user.is_active)
    )
generate_token = TokenGenerator()

def send_account_verification_email(user):
    uidb64 = urlsafe_base64_encode(force_bytes(user.pk))
    token = generate_token.make_token(user)
    # production email link
    verification_link = f'https://culture-lancer.vercel.app/account-verification/{uidb64}/{token}/'
    # verification_link = f'http://localhost:3000/account-verification/{uidb64}/{token}/'

    # Prepare email context
    context = {
        'user': user,
        'verification_link': verification_link,
    }

    # Render the HTML email template
    html_message = render_to_string('account_verification_email.html', context)
    plain_message = strip_tags(html_message)  # Fallback for email clients that don't support HTML

    # Send email
    send_mail(
        'Verify Your Email - CultureLancer',
        plain_message,
        settings.DEFAULT_FROM_EMAIL,
        [user.email],
        html_message=html_message,
    )
class ApplicantVerifyEmailView(APIView):
    
    """
    endpoint to verify email after signup pass the uidb64 and token
    
    """
    
    def get(self, request, uidb64,token):
        try:
            # Decode the UID and get the user and assessment ID
            uid = urlsafe_base64_decode(uidb64).decode()
            user = CareerUser.objects.get(pk=uid)
        except (TypeError, ValueError, OverflowError, CareerUser.DoesNotExist):
            return Response({'error': 'Invalid user ID'}, status=status.HTTP_400_BAD_REQUEST)
        # Check the token validity
        if user is not None and generate_token.check_token(user, token):
            user.is_active = True  # Activate user
            user.save()
            
            return Response({'message': 'Email verified successfully,'}, status=status.HTTP_200_OK)
        else:
            return Response({'error': 'Invalid token'}, status=status.HTTP_400_BAD_REQUEST)

Welcome @owolabi-develop !

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ok nice thanks for the correction