Ask HN: What open source visual workflow library do you use for your web app?

I’m a backend developer and am looking for a frontend visual workflow library to use for my web app. This library would be used to create the visual workflow to define actions by the user.

For example, customer.io has a drag & drop web workflow to define actions. Pictured at https://customer.io/wp-content/uploads/2021/06/use-case-upsell.svg

Does anyone know of a frontend library I can use to embed into my web app the drag & drop functionality to define workflow actions so that I can tie it into my backend?

Thanks in advance.