Take a look at https://dvblogic.com/wiki/index.php/How_to_make_a_custom_transponder_file
These .ini files are located in the Plex program folder
Plex Media Server/ Resources/ Tuner/ Shared/ scanners/ dvbc/ transponders
either find the one that is used for you and edit it or add a new one
see
Keep in mind that your edited file may get replaced or erased when you update Plex Media Server. So keep a copy of it in some safe storage location.
