In the home handler here: https://github.com/FACK1/Mylibrary/blob/master/src/server/homeHandler.js#L14
You are checking for a cookie, but you haven't set it in the login handler yet? I would probably set and check the cookie in the same PR - it's fine to split them out, but then it would make sense for the next immediate pull request to be setting the cookie!
you should sign the jwt and set the cookie here:
https://github.com/FACK1/Mylibrary/blob/master/src/server/handler.js#L84
Otherwise this is kind of pointless...