Unable to execute Node.js Synchronously and get the desired output

Question

Following is a simple nodejs code wherein a "https" request is being made to the API URL("https://jsonmock.hackerrank.com/api/medical_records"), to get the total count of patients having Blood Pressure Diastole within the given range(lowerlimit, upperlimit). But I am unable to get the desired output (count) due to asynchronous behaviour. I have searched for all workaround methods like "async/await&Promise", "callbacks", etc. but I am unable to implement it in this particular example which might indicate I haven't yet understood those workaround methods. I would appreciate any help in explaining these methods in simple ways and thus, solving my problem. Thank You!!

function myfunc(lowerlimit, upperlimit) {
  const https = require("https");
  var url = "https://jsonmock.hackerrank.com/api/medical_records"
  var totalPage;
  var count = 0;
  var medicalData;
  var results;
  var bloodPressureDiastole;
  https.get(url, function(res){
    res.on("data", function(data){
      medicalData = JSON.parse(data);
      totalPage = medicalData.total_pages;
    });
  });

  for (let i = 1; i <= totalPage; i++){
    url = url+"?page="+i.toString();
    https.get(url, function(res){
      res.on("data", function(data){
        medicalData = JSON.parse(data);
        results = medicalData.per_page;
        for (let j = 0; j < results; j++){
          bloodPressureDiastole = medicalData.data[j].vitals.bloodPressureDiastole;
          if (bloodPressureDiastole >= lowerlimit && bloodPressureDiastole <= upperlimit) {
            count++;
          }
        }
      });
    });
  }
  return count;
}
console.log(myfunc(80, 200));