I've run into an error in my code and I am a bit stuck

Question

I've been developing software and have ran into an issue with it.

#include <iostream>
#include <string>
#include <fstream>
#include <sstream>

void fileOP(std::ifstream testdata, std::string line, std::string csvitem, int linenumsought, int linenum);

int main(){
    std::ifstream testdata; testdata.open("testdata.txt");
    std::string line, csvitem;
    int linenum = 0;
    int linenumsought;
    std::string address;

    std::cout << "Please enter address: ";
    std::getline(std::cin, address);

    fileOP(testdata, line, csvitem, linenum, linenumsought, address);

    return 0;
}

void fileOP(std::ifstream testdata, std::string line, std::string csvitem, int linenumsought, int linenum) {

    if (testdata.is_open()) {
        while (std::getline(testdata, line)) {
            linenum++;

            if (linenum == linenumsought) {

                std::cout << line << '\n';
                std::istringstream myline(line);

                while(getline(myline, csvitem, ',')) {
                        std::cout << csvitem << '\n';
                }
            }
        }
    }
}

Its saying "Function cannot be referenced -- it is a deleted function" referring to the testdata and address variable in fileOP(testdata, line, csvitem, linenum, linenumsought, address);

I am a bit confused about what the error is and how to fix it.