How to login on employer computer without access to other organizations?

Is there a way to log into a Github account on an employer owned computer, without leaking credentials for access to other organizations accessible from that account? This would necessarily require not using an account password, since entering the password would expose it to the employers keylogger.

Background:
It appears widely recommended to use the same Github account for personal use and across multiple organizations. This appears convenient, and the ‘organizations’ feature is helpful for keeping things organized separately.