Creating a new PKI engine via REST API

I’m having trouble finding a route for creating a new pki engine via the REST API. All of the routes in the API documentation under PKI assume the existence of an engine.

Is there documentation on this route?

Any secret engine may be enabled through the API via the sys/mounts endpoint.

Documentation available at /sys/mounts - HTTP API | Vault by HashiCorp

Thank you very much!