Error LNK2019 in cpp file while csv file is attached to the file [duplicate]

Severity    Code    Description Project File    Line    Suppression State
Error   LNK2019 unresolved external symbol "bool __cdecl readCSVtovector(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::vector<class Record,class std::allocator<class Record> > &)" (?readCSVtovector@@YA_NV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@AAV?$vector@VRecord@@V?$allocator@VRecord@@@std@@@2@@Z) referenced in function _main  quiznewcsv  C:\Users\H A I E R\source\repos\quiznewcsv\quiznewcsv\main.obj  1