custom activation function with 2+ parameters logit price response function

Question

I understand that one can create a custom activation function in Keras as shown, for example, here.

I would like to create an ANN with 2 outputs to feed a and b into this logit price response function/custom activation function taken from here:

So a and b are produced from the dataset's features. The price is also in the dataset.

Does this make sense? Is this possible? Thanks!