A developer on XDA has devised a means of unlocking bootloaders of the Nokia 2, Nokia 5, Nokia 6, and Nokia 8. While testers have confirmed the fact that it does work, the methods involved may not be the safest.
https://www.notebookcheck.net/Nokia-users-can-now-unofficially-unlock-their-bootloaders-but-the-methodology-is-as-sketchy-as-it-gets.293912.0.html