How to pass a javascript variable to express to store in sqlite database?

Question

I am taking some values from a form and then storing them in browser's local storage to use them later

function getData(){
        var dear = document.getElementById("dear").value;
        var yours = document.getElementById("yours").value;

        localStorage.setItem("receiver", dear);
        localStorage.setItem("sender", yours);
      }

I also need to use these values in my sqlite database which I am navigating through express. how can i access either the javascript variable or localStorage to get to these values.

I have tried accessing localStorage directly but servers cannot access browser information, I have also tried using the variables directly but it seems that doesn't work either.