what does the “+ 1” mean?
answer_start = tf.argmax(
    answer_start_scores, axis=1
).numpy()[0]  # Get the most likely beginning of answer with the argmax of the score
answer_end = (
    tf.argmax(answer_end_scores, axis=1) + 1
).numpy()[0]  # Get the most likely end of answer with the argmax of the score