Grabbed dndbeyond's source code

```
~/go/bin/sourcemapper -output ddb -jsurl https://media.dndbeyond.com/character-app/static/js/main.90aa78c5.js
```

ddb_main/helpers/tokenUtils.ts

@@ -0,0 +1,15 @@
+import jwtDecode from "jwt-decode";
+
+import { AuthUtils } from "@dndbeyond/authentication-lib-js";
+
+import { authEndpoint as authUrl } from "../config";
+
+export const getStt = AuthUtils.makeGetShortTermToken({
+  authUrl,
+  throwOnHttpStatusError: false,
+});
+
+export const getDecodedStt = async () => {
+  const stt = await getStt();
+  return stt ? jwtDecode(stt) : null;
+};