from transformers import NllbTokenizer
tokenizer = NllbTokenizer.from_pretrained("facebook/nllb-200-distilled-600M")
tokenizer("How was your day?").input_ids
[13374, 1398, 4260, 4039, 248130, 2, 256047]
2: ''
256047 : 'eng_Latn'

New behaviour

thon

from transformers import NllbTokenizer
tokenizer = NllbTokenizer.from_pretrained("facebook/nllb-200-distilled-600M")
tokenizer("How was your day?").input_ids
[256047, 13374, 1398, 4260, 4039, 248130, 2]