Yes, this is option #2 on sharing your account. This can be done by going to Settings > Sharing > Invite Friend
Full read-up here: https://support.plex.tv/articles/204226753-friends/
This allows you to invite a friend via their already created user name or a newbie to Plex via just their email address. They then get a link to sign-up to Plex and when they do they have access to your library. I use this feature with my friends & Family, I share my account to about 12 individuals and they all have their own log-in and view history, etc…
