Implement a neural network with keras in python for ordinal regression.

Hi everyone I need to do a neural network for ordinal regression/classification with keras, the paper that implements it is Rank-consistent ordinal regression for neural networks. Explain me what is the problem with using a usual neural network arquitecture and how to implement the method of the paper. There is a stats exchange question that can be useful https://stats.stackexchange.com/questions/140061/how-to-set-up-neural-network-to-output-ordinal-data

Thank you all