TF2 Optimize an Input

So I trained a basic model, and I’d like to use that model to optimize an input.

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So if my input is [A, B, C, D, E] I’d like to specify to optimize A, B, and C while keeping the model, as well as D and E constant.

Using 2.7.0 with Keras in Python

I can find some examples with depracated code, but I am having trouble finding resources on how to set this up in TF2.