Installing VTK in Ubuntu 18.04

Hi Elvis,
I am trying to install VTK 8.2 that may be required for another application. So, I tried to follow the commands you provided, but I get the following error:

nanay001@nanay001-Bonobo-WS:~/vtk-inst$ git clone git@gitlab.kitware.com:vtk/vtk.git
Cloning into ‘vtk’…
git@gitlab.kitware.com: Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
nanay001@nanay001-Bonobo-WS:~/vtk-inst$

Please advise