Hello ,
Connecting FME Flow Hosted to a remote engine running on an on-premises or cloud-based virtual machine is fully supported. The process for installing the remote engine, configuring its connection to the core host, and executing job translations is identical to that of an on-premises FME Flow core or an in-cloud FME Flow core
No changes to access permissions are required on the Flow Hosted core, as all communication originates from the core side. However, if the remote engine is operating in a restricted network environment, ensure that the HTTPS port is open and the Flow Hosted URL is whitelisted to allow proper communication.
In this configuration, license request must be resubmitted for the remote engine. You can follow the steps outlined in this article to complete the licensing process.