The simplest way to try out your finetuned model for inference is to use it in a [pipeline]. Instantiate a pipeline for question answering with your model, and pass your text to it:

from transformers import pipeline
question_answerer = pipeline("question-answering", model="my_awesome_qa_model")
question_answerer(question=question, context=context)
{'score': 0.2058267742395401,
 'start': 10,
 'end': 95,
 'answer': '176 billion parameters and can generate text in 46 languages natural languages and 13'}