Coreference Resolution annotator is not working

[purvanshi]

I gave the data as
data="The Revolutionary War occurred during the 1700s and it was the first war in the U.S."
and then printed the token_dict after calling

token_dict = cn.arrange(data)
The printed dictionary I got-
{'lemma': ['the', 'Revolutionary', 'War', 'occur', 'during', 'the', '1700', 'and', 'it', 'be', 'the', 'first', 'war', 'in', 'the', 'U.S.'], 'normalizedNER': [0, 0, 0, 0, 0, '170X', '170X', 0, 0, 0, 0, '1.0', 0, 0, 0, 0], 'characterOffsetBegin': [0, 4, 18, 22, 31, 38, 42, 48, 52, 55, 59, 63, 69, 73, 76, 80], 'characterOffsetEnd': [3, 17, 21, 30, 37, 41, 47, 51, 54, 58, 62, 68, 72, 75, 79, 84], 'speaker': ['PER0', 'PER0', 'PER0', 'PER0', 'PER0', 'PER0', 'PER0', 'PER0', 'PER0', 'PER0', 'PER0', 'PER0', 'PER0', 'PER0', 'PER0', 'PER0'], 'ner': ['O', 'IDEOLOGY', 'CAUSE_OF_DEATH', 'O', 'O', 'DATE', 'DATE', 'O', 'O', 'O', 'O', 'ORDINAL', 'CAUSE_OF_DEATH', 'O', 'O', 'COUNTRY'], 'index': ['1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '14', '15', '16'], 'word': ['The', 'Revolutionary', 'War', 'occurred', 'during', 'the', '1700s', 'and', 'it', 'was', 'the', 'first', 'war', 'in', 'the', 'U.S.'], 'truecaseText': ['The', 'Revolutionary', 'War', 'occurred', 'during', 'the', '1700s', 'and', 'it', 'was', 'the', 'first', 'war', 'in', 'the', 'U.S.'], 'after': [' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ''], 'timex': [{'tid': 't1', 'value': '170X', 'type': 'DATE'}, {'tid': 't1', 'value': '170X', 'type': 'DATE'}], 'truecase': ['INIT_UPPER', 'INIT_UPPER', 'INIT_UPPER', 'LOWER', 'LOWER', 'LOWER', 'LOWER', 'LOWER', 'LOWER', 'LOWER', 'LOWER', 'LOWER', 'LOWER', 'LOWER', 'LOWER', 'UPPER'], 'originalText': ['The', 'Revolutionary', 'War', 'occurred', 'during', 'the', '1700s', 'and', 'it', 'was', 'the', 'first', 'war', 'in', 'the', 'U.S.'], 'pos': ['DT', 'NNP', 'NNP', 'VBD', 'IN', 'DT', 'NNS', 'CC', 'PRP', 'VBD', 'DT', 'JJ', 'NN', 'IN', 'DT', 'NNP'], 'before': ['', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ']}
There is no key of Dcoref here.