how to enter pin
Here’s the support page on how to change or rest your PIN
https://support.plex.tv/hc/en-us/articles/204245033-I-forgot-my-Plex-Account-PIN-how-can-I-reset-it-How-can-I-change-my-PIN-
But if you are look for info on where to enter the LINK code that the Plex app displays you would use this link
https://plex.tv/link
