So Jellyfin by default uses The Movie Database. However, you can manually direct Jellyfin to use The TV Database for specific TV shows if you want. You just have to rename the Series folder. In The TVDB, Pokemon Journey's is Season 19.
To have JF use The MovieDB, you have your rename the Series folder: Pokémon (1997) [tmdbid-60572]. To use the TVDB, the Series folder would be renamed to: Pokémon (1997) [tvdbid-76703].
Unfortunately, JF doesn't support IMDB for TV. Only movies. Neither is ideal for your use-case though. Sorry dude.