Italian phonetic doesn't work

[ghost]

We are trying to use phonemizer for italian language, using "it-it" language code as the documentation says but the json results always give None on "phonemes" field.

We tried the en-us language code, and it works correctly.

We also tried this code given by the documentation:

from gruut import sentences

ssml_text = """<?xml version="1.0" encoding="ISO-8859-1"?>
<speak version="1.1" xmlns="http://www.w3.org/2001/10/synthesis"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.w3.org/2001/10/synthesis
                http://www.w3.org/TR/speech-synthesis11/synthesis.xsd"
    xml:lang="en-US">
<s>Today at 4pm, 2/1/2000.</s>
<s xml:lang="it">Un mese fà, 2/1/2000.</s>
</speak>"""

for sent in sentences(ssml_text, ssml=True):
    for word in sent:
        if word.phonemes:
            print(sent.idx, word.lang, word.text, *word.phonemes)

With this expected outuput:

0 en-US Today t ə d ˈeɪ
0 en-US at ˈæ t
0 en-US four f ˈɔ ɹ
0 en-US P p ˈi
0 en-US M ˈɛ m
0 en-US , |
0 en-US February f ˈɛ b j u ˌɛ ɹ i
0 en-US first f ˈɚ s t
0 en-US , |
0 en-US two t ˈu
0 en-US thousand θ ˈaʊ z ə n d
0 en-US . ‖
1 it Un u n
1 it mese ˈm e s e
1 it fà f a
1 it , |
1 it due d j u
1 it gennaio d͡ʒ e n n ˈa j o
1 it duemila d u e ˈm i l a
1 it . ‖

But we have this output:

0 en-US Today t ə d ˈeɪ
0 en-US at ˈæ t
0 en-US four f ˈɔ ɹ
0 en-US P p ˈi
0 en-US M ˈɛ m
0 en-US , |
0 en-US February f ˈɛ b j u ˌɛ ɹ i
0 en-US first f ˈɚ s t
0 en-US , |
0 en-US two t ˈu
0 en-US thousand θ ˈaʊ z ə n d
0 en-US . ‖
1 it , |
1 it . ‖

Why it does not work correctly with italian language?