Why we can't use stride and dilation rate at the same time in causal convolution?

Question

I would like to understand why we can't use a stride different from 1 and a dilation rate different from 1 at the same time.

The following code will raise an error:

c1 = Conv1D(filters=64, kernel_size=5, strides=2, padding='causal',dilation_rate=2, activation='relu')(input_layer)

I want to use them at the same time, but i can't. (I'm using Tensorflow & Keras)