used Multer Middleware.To check from backend you should go to body-->form-data-->in key box choose File and name the same field name as in Schema and in its keyvalue click Select files to upload
1).Go to setting on top right or ctrl+coma Then look at working directory i.e the problem. So Go to location of postman in your local system,C drive.Then change name of folder postman-agent into postman.Theregoes, you can upload file