How to use the Plex Poster Assistant - jamiebclark/plex-poster-assistant GitHub Wiki
Usage
Clicking the Chrome Extension button will display a window that will allow a user to enter an image URL. The user can then search through their Plex library to find the corresponding item, and then set the poster art.

Compatible Sites
The Poster Assistant should be able to detect posters from the following sites:
Setup

Local Plex URL
You'll need to provide the local URL of your Plex server. This will include the protocol and the ports. Something like http://192.168.0.1:32400. You can find this value in the Remote Access portion of Plex's support material. You can use the Private URL if you're on the same network as Plex, or the Public URL if you're not. Just be sure to include a protocol (http:// or https://).
Plex Token
You'll also need the Plex Token. Plex provides an article on how to retrieve your Plex Token