Vaccine machine :!/bin/bash not work?

Hello friends, I am trying to raise privileges to root on the vaccine machine, from the file “/etc/postgresql/11/main/pg_hba.conf” but, after editing it with:! / Bin / bash and saving the changes it does not work. My question is, where is my fault?

bump

did you use sudo? else vi will run in the context of the current user, not as the root user.