Problem in Chapter 10 NLP!

Greetings!
I have been working on a multilabel text classification model as in chapter10 towards the end.
The classifier has been fine-tuned and shows the epoch, train_loss, valid_loss, accuracy etc.

What is shown in the chapter is a trained learner giving results on the validation set. This looks nice on paper, but how do I take this learner and apply it on another test file?