VTK confusion

hello,

I was used to perform simulations using old version of LIGGGHTS which was not installed by me (i.e. I don't know how was it compiled), and I was using the "dump" command with "custom/vtk" normally, leading to the execution of .vtk files.
Now, I want to work on a newer version of LIGGGHTS that I compiled without the usage of VTK, so I thought about adding into the Makefile.user the path of the vtk package that has been used by the oder version, but when I opened the (LIGGGHTS-PUBLIC-master>lib>vtk) folder in the old version, I found it to be empty, so I was confused how the vtk in the old version was considered although this folder is empty. I even was not able to find any vtk relation with the old version.

So may you please tell me how to know how .vtk files where executed although no vtk package was found by me in the old verion's folders inorder for me to apply the same thing for the new version of LIGGGHTS and be able to get .vtk files without using AutoInstall option.

best wishes,