Accented sentences produce a utf error

[drazde]

After asking a question with an accent (eg: è) in the sentence, the next question gives this error:

// API ERROR: Your request contained invalid JSON: 'utf-8' codec can't decode byte 0xe8 in position 306: invalid continuation byte

NB: in the folder nvim-data\chatgpt the json are encoded with UTF-8

Do i have to put something in my configuration?