Package suggestion to calculate Protein-Protein interaction.

Question

[UGUR]

Hi guys, I am searching any basic tools that can predict the free binding energy between the proteins from it's pdb files, I'm working at a project always mutates the proteins and we need to recalculate the binding energy between defined proteins like a WT protein get a mutation it's specific binding site, after that we should predict how it's binding energy to specific ligand is changed. FoldX is a good package for that but I cannot find any manuel for FoldX analyse complex. Can anyone share any manuel for or example/tutorial for that or can suggest any alternative (faster package) ? also I need a database that can show protein's specific binding domains if anyone can suggest.

Thank you :)