Thank you so much
@SylviaB for your enormous help. But I have already resolved this network error by searching online. The same solutions discussed in that article what you suggested above.
Mainly the problem was resolved by following the browser extension and clearing the browser cache.
But I knew a new thing from that article that there is a high traffic at 1-4pm and generally I was searching at that time. I dont know it may be for that reason I was getting the error. But anyway now there is no network error in ChatGPT and really I am getting the response from ChatGPT better than before.
Thank you.