Add the callback to fit, and 🤗 Transformers will push the trained model to the Hub:

model.fit(tf_train_dataset, validation_data=tf_validation_dataset, epochs=3, callbacks=push_to_hub_callback)

Use the push_to_hub function
You can also call push_to_hub directly on your model to upload it to the Hub.
Specify your model name in push_to_hub:

pt_model.push_to_hub("my-awesome-model")