Create two keys for bitbucket and github

mkdir sshkey
ssh-keygen -t rsa -C "company" -f "company"
ssh-keygen -t rsa -C "JTNOMONEY" -f "JTNOMONEY"

Clear cached key

ssh-add -D

Add two keys and check afterwards

ssh-add ~/sshkey/company
ssh-add ~/sshkey/JTNOMONEY
ssh-add -l

If ssh-add is not working, try

eval "$(ssh-agent)"

Add a config files ./ssh/config

#--Company's bitbucket
Host bitbucket.company.com.tw
  HostName bitbucket.company.com.tw
  IdentityFile ~/.ssh/company

#--JTNOMONEY github
Host github.com
  HostName github.com
  IdentityFile ~/.ssh/JTNOMONEY

Set an example of default name/email using git config and check settings

#--Company's bitbucket
git config --global user.name "company_name"
git config --global user.email "company_name@company.com"
git config --list

Add your ssh public keys on github/bitbucket, then test github account for example:

git clone git@github.com:JTNOMONEY/jtnomoney.github.io.git
jtnomoney.github.io$ git config user.name "jtnomoney"
jtnomoney.github.io$ git config user.email "jtnomoney@gmail.com"