//jQuery
$("#resetbtn").click(()=> {
 // post to backend
 $.post("data.php", {reset:true, userid:userid}, (data)=> {
  // sends request and will respond with temporary password
 });

//PHP
<?php
 if(isset(/* front end data*/)) {
  UPDATE users set password = /* temporary generated pw 
  from php */, pwreset = 1, pwresetexpire = /* 2 hour reset 
  limit in format of Y:m:d H:i*/
 }
// user enters temp password, updates to new
 if(isset(/*new pw*/)){
  update users set pwreset = 0, pw = /*new pw*/, 
  pwresetexperire = ""
  
  // logs generated here
 }
?>