interoperability – Calling Julia via `ExternalEvaluate`

I am trying to call Julia from Mathematica via ExternalEvaluate, as per this documentation page. I have Julia installed with all the required packages (ZMQ, JSON, and LinearAlgebra), but FindExternalEvaluators("Julia") still cannot find Julia. The documentation page has no further information. How can I get Mathematica to find my Julia installation? Perhaps it just doesn’t know the right place to look?