Hi as it can be clearly seen from the graph that your model is not learning. Can you share the model that you have used as in the blog you can see that I have build a very basic model in which at the last layer I have used sigmoid function so your value should be in float. So please share the snapshot of the model used and the hyperpameters along with the Data tab.

Ok if you want to use softmax function instead of sigmoid then it must be a classification problem. Softmax function converts the probability sum to 1 since you have only 1 value as output its value is 1.
If you want to use softmax then change the datatype of the output variable to categorical and the output dimension of the last layer to 2 from 1.