If they are using an engine to console pairing direction, I would refer to this post which outlines that process end to end: Orchestrating InsightVM Scan Engine Deployment
In the case of engine to console, the engine will automatically be added to the console when it attempts to connect. To automatically finish the pairing process, the engine can be provisioned with a shared secret that was retrieved from the console prior, or the engine can be approved on the console. There is no API endpoint to approve an engine in the engine to console pairing direction, so the only fully automated way is for the engine to be configured with the shared secret.