disable links on the first Multistep form

Hi,

I would like to disable links on the first Multistep form under certain conditions.
I had the idea to do this with javascript, but that’s not very clean.
is there any methods to do it automatically ??
is anybody can help me?

Thanks a lot !!

Drupal version: 


Source: https://www.drupal.org/taxonomy/term/4/feed