"amqp://localhost". Be sure that you call the middleman with this connection string.
"amqp://localhost?heartbeat=60", and update your SitecoreDXG Generation Server's
./settings.jsfile with the updated connection string value. The heartbeat parameter will help to keep the connection alive. Note that you do not need to call the Middleman with the heartbeat parameter.
services.mscinto the Windows Start Menu), find the SitecoreDXG Generation Service in the list and restart it.