These are translations of the Ubuntu software package messages, donated by the Ubuntu community.
To load a language pair which isn't part of the config, all you need to do is specify the language code as pairs.
You can find the valid pairs in Homepage section of Dataset Description: http://opus.nlpl.eu/Ubuntu.php
E.g.
dataset = load_dataset("opus_ubuntu", lang1="it", lang2="pl")
Supported Tasks and Leaderboards… See the full description on the dataset page: https://huggingface.co/datasets/Helsinki-NLP/opus_ubuntu.