You would need to write you custom Dataset loading class.
Please refer to: Writing a dataset loading script — datasets 1.9.0 documentation 191
You don’t have to register your dataset, just create a MyDataset.py class that looks similar to the tutorial.
You can also take a look at the actual implementations of existing datasets: datasets/squad.py at master · huggingface/datasets · GitHub 57
What you’d need to do is define the Features in the _info() function relevant to your data, and modify  generate_examples which holds logic in loading the data