Setting ffmpeg analyzeduration and probesize values on linux install

Hi,

Moved from Plex to Emby and now to Jellyfin - fantastic media server. One thing I’ve been unable to work out is how to set analyzeduration and probesize vales for ffmpeg. I want to do this as when playing iptv, i get no audio most of the time with the error;

unspecified size
Consider increasing the value for the ‘analyzeduration’ and ‘probesize’ options

I have read that in Windows these can be set using env variables, but have not seen how to set in Linux,

I have installed version 10.6.4 stable on Debian Buster.

Many thanks for any help.
Chris

Update: Could not get IPTV channels to work through Live TV function. Added channels individually to IPTV Plugin and they all work flawlessly.