Could you please tell me how I should modify the training file when I replace the binary classification task with a multi-classification task? Thank you for your open source.

python train.py
Sanity Checking DataLoader 0: 0%| | 0/2 [00:00<?, ?it/s]Traceback (most recent call last):
File "/sty/audio/train.py", line 147, in
main()
File "/sty/audio/train.py", line 135, in main
trainer.fit(model=lit_model, train_dataloaders=train_loader, val_dataloaders=val_loader)
File "/root/anaconda3/envs/audio/lib/python3.10/site-packages/pytorch_lightning/trainer/trainer.py", line 608, in fit
call._call_and_handle_interrupt(
File "/root/anaconda3/envs/audio/lib/python3.10/site-packages/pytorch_lightning/trainer/call.py", line 38, in _call_and_handle_interrupt
return trainer_fn(*args, **kwargs)
File "/root/anaconda3/envs/audio/lib/python3.10/site-packages/pytorch_lightning/trainer/trainer.py", line 650, in _fit_impl
self._run(model, ckpt_path=self.ckpt_path)
File "/root/anaconda3/envs/audio/lib/python3.10/site-packages/pytorch_lightning/trainer/trainer.py", line 1103, in _run
results = self._run_stage()
File "/root/anaconda3/envs/audio/lib/python3.10/site-packages/pytorch_lightning/trainer/trainer.py", line 1182, in _run_stage
self._run_train()
File "/root/anaconda3/envs/audio/lib/python3.10/site-packages/pytorch_lightning/trainer/trainer.py", line 1195, in _run_train
self._run_sanity_check()
File "/root/anaconda3/envs/audio/lib/python3.10/site-packages/pytorch_lightning/trainer/trainer.py", line 1267, in _run_sanity_check
val_loop.run()
File "/root/anaconda3/envs/audio/lib/python3.10/site-packages/pytorch_lightning/loops/loop.py", line 199, in run
self.advance(*args, **kwargs)
File "/root/anaconda3/envs/audio/lib/python3.10/site-packages/pytorch_lightning/loops/dataloader/evaluation_loop.py", line 152, in advance
dl_outputs = self.epoch_loop.run(self._data_fetcher, dl_max_batches, kwargs)
File "/root/anaconda3/envs/audio/lib/python3.10/site-packages/pytorch_lightning/loops/loop.py", line 199, in run
self.advance(*args, **kwargs)
File "/root/anaconda3/envs/audio/lib/python3.10/site-packages/pytorch_lightning/loops/epoch/evaluation_epoch_loop.py", line 137, in advance
output = self._evaluation_step(**kwargs)
File "/root/anaconda3/envs/audio/lib/python3.10/site-packages/pytorch_lightning/loops/epoch/evaluation_epoch_loop.py", line 234, in _evaluation_step
output = self.trainer._call_strategy_hook(hook_name, *kwargs.values())
File "/root/anaconda3/envs/audio/lib/python3.10/site-packages/pytorch_lightning/trainer/trainer.py", line 1485, in _call_strategy_hook
output = fn(*args, **kwargs)
File "/root/anaconda3/envs/audio/lib/python3.10/site-packages/pytorch_lightning/strategies/strategy.py", line 390, in validation_step
return self.model.validation_step(*args, **kwargs)
File "/sty/audio/train.py", line 62, in validation_step
return self.get_step_metrics(batch)
File "/sty/audio/train.py", line 36, in get_step_metrics
logits = self.model(mfcc)
File "/root/anaconda3/envs/audio/lib/python3.10/site-packages/torch/nn/modules/module.py", line 1194, in _call_impl
return forward_call(*input, **kwargs)
File "/sty/audio/model/transformer_cls.py", line 37, in forward
final_feature_map = encoded_features[:, -1, :]
IndexError: index -1 is out of bounds for dimension 1 with size 0

Can you give me an example of a JSON file dataset? I kept getting errors while loading the data