public async Task <AchievementResponse> DeleteAsync(int id)
        {
            var existingAchievement = await _achievementRepository.FindById(id);

            if (existingAchievement == null)
            {
                return(new AchievementResponse("Achievement not found"));
            }

            try
            {
                _achievementRepository.Remove(existingAchievement);
                await _unitOfWork.CompleteAsync();

                return(new AchievementResponse(existingAchievement));
            }
            catch (Exception ex)
            {
                return(new AchievementResponse($"An error ocurred while deleting achievement: {ex.Message}"));
            }
        }