I am new to pytorch and I am trying to understand how to enable CUDA in an anaconda environment.
I have created my conda env with the following commands
conda create --name env_name
conda activate env_name
conda install -c conda-forge -c pytorch python=3.7 pytorch torchvision cudatoolkit=10.1 opencv numpy pillow

Then I run the following file:
import torch
import torchvision

print("PyTorch Version: ",torch.__version__)
print("Torchvision Version: ",torchvision.__version__)

if torch.cuda.is_available():
    print("if torch.cuda.is_available() returns TRUE")
else:
    print("if torch.cuda.is_available() returns FALSE")

torch.zeros(1).cuda()

And I get
ython sources/torch_cuda_setup_check.py 
PyTorch Version:  1.10.0
Torchvision Version:  0.10.0a0
if torch.cuda.is_available() returns FALSE
Traceback (most recent call last):
  File "sources/torch_cuda_setup_check.py", line 12, in <module>
    torch.zeros(1).cuda()
  File "/home/fabrizioschiano/anaconda3/envs/deeplabv3finetuning/lib/python3.7/site-packages/torch/cuda/__init__.py", line 208, in _lazy_init
    raise AssertionError("Torch not compiled with CUDA enabled")
AssertionError: Torch not compiled with CUDA enabled

Could you help me understanding how to install a version of torch which has CUDA enabled?
I am sure that my system has a GPU.
More details about my system can be found below.

I am on Ubuntu 20.04 
The command:
nvcc --version

gives the following output
nvcc: NVIDIA (R) Cuda compiler driver
Copyright (c) 2005-2019 NVIDIA Corporation
Built on Sun_Jul_28_19:07:16_PDT_2019
Cuda compilation tools, release 10.1, V10.1.243

The command:
nvidia-smi

gives the following output
Tue Nov 23 17:44:11 2021       
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 470.82.00    Driver Version: 470.82.00    CUDA Version: 11.4     |
|-------------------------------+----------------------+----------------------+
| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
|                               |                      |               MIG M. |
|===============================+======================+======================|
|   0  NVIDIA GeForce ...  Off  | 00000000:01:00.0  On |                  N/A |
| N/A   54C    P0    25W /  N/A |    833MiB /  7973MiB |      1%      Default |
|                               |                      |                  N/A |
+-------------------------------+----------------------+----------------------+
                                                                               
+-----------------------------------------------------------------------------+
| Processes:                                                                  |
|  GPU   GI   CI        PID   Type   Process name                  GPU Memory |
|        ID   ID                                                   Usage      |
|=============================================================================|
|    0   N/A  N/A      1082      G   /usr/lib/xorg/Xorg                102MiB |
|    0   N/A  N/A      1693      G   /usr/lib/xorg/Xorg                405MiB |
|    0   N/A  N/A      1823      G   /usr/bin/gnome-shell              130MiB |
|    0   N/A  N/A      2306      G   ...AAAAAAAAA= --shared-files      139MiB |
|    0   N/A  N/A      4719      G   .../debug.log --shared-files        2MiB |
|    0   N/A  N/A     13922      G   ...AAAAAAAAA= --shared-files       37MiB |
+-----------------------------------------------------------------------------+