​
Passing the ref id programmatically

fpr("init",{cid:"...",ref_id:"..."}) Getting the ref id from the url and passing it to fpr init 
<script>(function (w) { w.fpr = w.fpr || function () { w.fpr.q = w.fpr.q || []; w.fpr.q[arguments[0] == 'set' ? 'unshift' : 'push'](arguments); }; })(window);

  function getQueryParameter(qParam) {
    var searchParams = new URL(document.location.toString()).searchParams;
    if (searchParams.has(qParam)) {
      return searchParams.get(qParam);
    } else {
      return null;
    }
  }

  var customRefValue = getQueryParameter("aff");
  if (customRefValue) {
    fpr("init", { ref_id: customRefValue, cid: "xxxxxx" });
  } else {
    fpr("init", { cid: "xxxxxxx" });
  }
</script>
<script src="https://cdn.firstpromoter.com/fpr.js" async></script>

​
Passing the ref id programmatically from a query string

<script>(function(w){w.fpr=w.fpr||function(){w.fpr.q = w.fpr.q||[];w.fpr.q[arguments[0]=='set'?'unshift':'push'](arguments);};})(window);
function getParam(param) {
return new URLSearchParams(window.location.search).get(param);
}
var ref_id = getParam("sa");
if (ref_id) {
fpr("init", { ref_id, cid: "xxxxxx" });
} else {
fpr("init", { cid: "xxxxxx" });
}
fpr("click");
</script>
<script src="https://cdn.firstpromoter.com/fpr.js" async></script>

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Forcing a new tid to be created or reinitializing the FirstPromoter cookies

You can force a new tid to be created by invalidating the old one this can be done by passing cookie_ref_id: ‘xxx’ as shown in the example below 
fpr("referral",{email: getParam("wj_lead_email")}, function(){
window.fpr("click",{cookie_ref_id: 'xxx'});
});
it can also be used to force new emails to be collected on page refresh 
<script>(function(w){w.fpr=w.fpr||function(){w.fpr.q = w.fpr.q||[];w.fpr.q[arguments[0]=='set'?'unshift':'push'](arguments);};})(window);
fpr("init", {cid:"…"});
fpr("click",{cookie_ref_id: 'xxx'});
</script>

​
Setting a default Promoter

<script>
  function getParam(param) {
    return new URLSearchParams(window.location.search).get(param);
  }

  (function (w) {w.fpr = w.fpr || function () {w.fpr.q = w.fpr.q || []; w.fpr.q[arguments[0] == 'set' ? 'unshift' : 'push'](arguments);};})(window);
  var hasTid = document.cookie.indexOf('fprom_tid=') > 0;
  var hasRefId = document.cookie.indexOf('fprom_ref=') > 0;

  if ((!hasRefId || !hasTid) && !getParam('fpr')) {
    var ref_id = "pm";
    fpr("init", {ref_id, cid: "xxxxxx"});
  } else {
    fpr("init", {cid: "xxxxxx"});
  }
  fpr("click");

</script>

<script src="https://cdn.firstpromoter.com/fpr.js" async></script>