Signing into Backand Using BackAnd SDK - backand

Question

Attempting to sign in (and enter a session) using user credentials in an Angular app using the Backand SDK. From the Backand docs I am attempting to sign in using the Backand.signin() method (from my local) which looks to be initially sending an OPTIONS http request to the API which unfortunately is causing this cross origin error:
XMLHttpRequest cannot load https://api.backand.com/token. Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:xxxx' is therefore not allowed access. The response had HTTP status code 400.
The exact response from the endpoint is: {"error":"unsupported_grant_type"}
I've combed through the documentation extensively but can't find anyone else having these errors.
This is exact code I am using:
function Login(username, password, callback) {
Backand.signin(username, password).then(function(response){
console.log(response);
}, function(error){
console.log(error);
});
}
The error is logged to the console as a null object.

Answer 1

It looks like the error was in fact on my end.
While attempting to set up my own Authorization service in my Angular app I inadvertently was adding an encoded Authorization token header somehow. When the requests were being made to Backand from the Backand SDK, the headers were not correctly set and thus causing issues.