I wonder if it is possible to interact with the mutagenesis wizard from the command line?

I am trying to determine best mutants for FRET labelling, by predicting the pka value/reactivity for a possible cysteine.

I would like to make a script that loops over the residues in my protein, change the residue to a cysteine, save the molecule and then initiate propka to get the pka for the cysteine.

I have googled myself to:

fetch 4ins, async=0
wizard mutagenesis

But I get:
Error: please select an atom, not a bond.

Can someone help here?