Actually this was the first thing I tried but it results into error like this:
Starting training for 300 epochs...

     Epoch   gpu_mem      GIoU       obj       cls     total   targets  img_size
     0/299     8.92G   0.03446    0.1387         0    0.1732         2      1280
               Class      Images     Targets           P           R      mAP@.5  mAP@.5:.95:   0%|                                                                                 | 0/124 [00:00<?, ?it/s]
Traceback (most recent call last):
  File "train.py", line 438, in <module>
    train(hyp, opt, device, tb_writer)
  File "train.py", line 301, in train
    results, maps, times = test.test(opt.data,
  File "/home/kamal/Documents/PyTorch_YOLOv4/test.py", line 206, in test
    plot_images(img, output_to_target(output.cpu(), width, height), paths, str(f), names)  # predictions
AttributeError: 'list' object has no attribute 'cpu'

It starts training but somehow when it calls the test function, it fails to load the tensor.