[BUG] Can't sync watched between emby, plex and jellyfin

[MrJosu]

Hello, thank you for your amazing work
I have issue to start this app in Unraid docker container
I have emby, jellyfin and plex with multiple users
But so far it detects only users with same login on diff apps, but my login for example is meccu on plex and emby, and meccuu on Jellyfin.
How to use this row? I believe this is solution, but I am not smart enough to figure out myself
Container Variable: USER_MAPPING
Map usernames between servers in the event that they are different. Syntax: JSON map.
And seems like something wrong with Emby - as only what I have about emby in logs
[DEBUG]: emby Server 0 info: Emby Fort: 4.8.10.0
Server 1: Plex: Plex Fort: 1.41.1.9057-af5eaea7a
Server 2: Jellyfin: Jellyfin JLIB: 10.10.0
[INFO]: Creating users list

[crowtrobot]

This is what works for me. In Plex I am crowtrobot and in jellyfin I am tomservo, so for USER_MAPPING I have:
USER_MAPPING = { "crowtrobot": "tomservo" }