frontend side data is not getting update automatically but when i refresh the page then it is updating
Means How can i Update Data and Page Content Without Reloading Using javascript

this i use for backend api

 function buttonClick(city, country, apiUrl) {



            var formData = new FormData();
            formData.append('city', city);
            formData.append('country', country);


            fetch(apiUrl, {
                method: 'POST',
                body: formData
            })


  }