CORS Error

[DillonArnold]

Hello all, 

My companies GIS team has created a ArcGIS REST API for us developers to use. It allows us access to the GIS data so we can display the GIS data on our frontend products. I currently have created an endpoint that queries a data layer and returns the query in GeoJSON format. The requests work great on Postman (as expected) however when I make a request from our staging environment in development I get this CORS error. 

Access to XMLHttpRequest at '<our endpoint>' from origin 'https://allocommunidev.wpenginepowered.com' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: Redirect is not allowed for a preflight request.

My question becomes, is this a frontend CORS error? From what I have read ArcGIS allows ALL cross origin requests which leads me to believe this is a frontend error, but I have no good way to tell and be certain. However I have tried many things. This is the jQuery and AJAX request. Any help would be much appreciated

$.ajax({
  url: tokenEndpoint,
  type: "POST",
  data: {
   username: username,
   password: password,
   client: "referer",
   referer: "https://stgallocomm.wpenginepowered.com",
   expiration: 60,
  },
  success: function (response) {
   if (response) {
    console.log(response);
    let token = response;
    
    $.ajax({
     url: NeCentralPons,
     type: "GET",
     beforeSend:
      function (xhr) {
       xhr.setRequestHeader('Authorization', `Bearer ${token}`);
       console.log(`Bearer ${token}`);
      },
     success: function (data) {
      console.log(data);
     },
     error: function (error) {
      console.error(error.status)
     }
    });
   } else {
    console.error("Token failed:", response);
   }
  }
});