[cuddlecake]

The underlying concept would be akin to Business Process Modelling.

Using something like https://camunda.com [0], you can execute a business process model. Such a model can include sending emails, waiting for responses, human action, custom API requests, etc.

Camunda is not no-code, but it comes close to what you imagine. I suspect that when the existing API landscape of a company needs to be used for workflows, coding/integration is inevitable.

There's also (truly) no-code platforms like https://bryter.com

[0]: I only know of this because there's a department at my current job that specializes in implementing workflows using camunda. I got explanations for it during moderate drinking, so my recounting of it may be incorrect in parts.