Client-Initiated Forms SSO javascript

I have a website which requires SSO. I am not a javascript programmer however my understanding is that it uses angularjs. I see the following code requesting the userid and password:

<div class="panel-body">
  <div class="form form-inline" style="max-width: 200px; margin: auto;">
    Username: 
    <input type="text" class="form-control" ng-model="credentials.userid" id="loginUserid">
    Password: <input type="password" class="form-control" ng-model="credentials.passwd" ng-keypress="checkEnter($event)">
    <button type="button" class="btn btn-primary" ng-click="login()">Login</button>
  </div>

When the user presses the login button, I see the following payload being posted to the server:

{action: "login", userid: "myuserid", passwd: "mypassword", junk: "2022-08-17T14:13:52.815Z"}
    action: "login"
    junk: "2022-08-17T14:13:52.815Z"
    passwd: "mypassword"
    userid: "myuserid"

I am using Client Initiated Forms based SSO. I am able to detect the login page as well as a successful login however I do not know how to send the json object above. I am looking for help with the extra javascript which I believe needs to be added.

Thanks

APM v16