Last Year's Essays Answers for My New Chevening Application - Is it acceptable?

It is not acceptable for you to use the same essay you used previously for your Chevening application. Since you were short listed for an interview but declined, you will have a hard time getting a second consideration for the scholarship. If the other candidates have stronger credentials that you do this year, then your rehashed essay isn't going to work. You must instead write new essays that will show how, even though you declined the shortlist interview last year, you have managed to further improve your credentials, making you an even stronger candidate this year, worthy of a second consideration. You can mention, where applicable that you declined the interview last year. Just make sure you don't make yourself sound too pitiful. The pity factor will not help. An improved credential list will work better in this case.

Thank you so much for your explanations. But I have a clarification, I applyed for Chevening three times, the first one in 2018 my application was rejected, 2019 I was selected for the intervew and things didn't wor, and the last time in 2020 and I used the same essays of 2019 & was selected for the interview but I apologized and didn't go for the intervew. I will try my best to make recognizable changes.

Thank you.