setting a permanent environment variable

Question

I am trying to permanently add an environment variable in ubuntu 16.04.3 LTS.

I have tried many of the online solutions but none are working.

I have tried adding:

export PLINK_PATH=/usr/local/bin/plink-1.07-x86_64
export PLINK_PATH
export PATH=$PATH:PLINK_PATH

in ~/.bashrc, ~/.profile, and ~/.bash_profile

and when I do

echo $PATH and printenv

it does not show the path I want.

I am logging into the computer over ssh, I am not sure if this has anything to do with it.

Any advice or help will be greatly appreciated :)

Thanks :)