With the Temperature value, you set how imaginative the chatbot's responses should be. The lower the value, the more sober the answers will be. The higher the value, the more imaginative.
The ideal value for you depends largely on the scenario in which you want to use the chatbot and also on the personality you give it. A good average value for the Temperature is 0.7.
Try different settings to find the best value for you. If you notice, for example, that the chatbot is repeating itself, then increase the Temperature. If you notice that it is rambling too much, then lower the value slightly.
Set the Temperature in the ChatGPT menu:
Set the Temperature in the web interface: