c – how can i fix it? LNK2019 LNK2019 unresolved external symbol _CreateProducts

how can i fix these errors? Error LNK2019 unresolved external symbol _fscnaf referenced in function _main Project44Severity Code Description Project File Line Suppression State Error LNK2019 unresolved external symbol _Error_msg referenced in function _main Project44 Error LNK2019 unresolved external symbol _CreateProducts referenced in function _main Project44 #include<stdio.h> #include<stdlib.h> #include<string.h> #include<math.h> typedef struct Item { char* … Read more