Once I've created a signing request on the backend, how do I redirect a user to the signing request on the frontend?

I've got an API endpoint that creates a signing request, like this:

const subscription = await Xumm.payload
.createAndSubscribe(request, (event) => {
// .... more logic, the end result is an object with a link, etc...

How do I take this information, and show the signing request on the frontend? I assume I use the jwt SDK for this, and probably need to pass the UUID? I was able to "hack" it by doing window.open([link]) to the link returned (subscription.created.next.always), but then after signing it doesn't return to the app.

Thanks!