Chat GPT response in API is not getting limited by words

Hi I am Using chat GPT API version 13 June 2023

In Prompt I have asked to send response within 100 words , but the response exceeds the limit and most of the responses come in 175-200 words

Whats the solution in this so that the response always comes in desired word count ?

There is no way to get a word count exactly, if you place the instruction to produce approximately 100 words in the system message then you will get around that +/- 25-50 words.

It is a feature of autoregressive networks used in the GPT models.