How to train model by tf.data in > TF 2.1

In the example of tensorflow TFRecord and tf.train.Example  |  TensorFlow Core, the dataset contains four feature: f0,f1,f2,f3.

If now we take f3 as the model result. How to use f0 and f3train model

for f0,f1,f2,f3 in dataset:
    model.fit(f0,f3,...)

My test shows that my model did not learn anything in this loop. Why, plz?