If there is no need to replace the digits in "numbers_N1", is it allowed to make it empty?
},
"numbers_N1": { },
"numbers_N2": {
Or, is it allowed to completely remove it?
},
"numbers_N2": {
In ja.tts, "numbers_N1" doesn't contain the words to replace but only digits like follows.
"numbers_N1": {
"1": "1",
"2": "2",
"3": "3",