The discovery hub does not show up on my QB2021 Pro, since I added these lines to my Windows host file:

127.0.0.1 alerts.accnts.intuit.com
127.0.0.1 sci.intuit.com
#127.0.0.1 assets.intuitcdn.net
#127.0.0.1 oauth.platform.intuit.com
127.0.0.1 qbdtipd.qbinproduct.intuit.com
127.0.0.1 edge.experimentation.intuit.com
127.0.0.1 tcontent.quickbooks.com
127.0.0.1 http-download.intuit.com
127.0.0.1 qb31bgocd.quickbooks.com
127.0.0.1 qb31bgpatch.quickbooks.com
#127.0.0.1 webconnectorclientapp.config-cdn.a.intuit.com
#127.0.0.1 accounts.intuit.com
127.0.0.1 trinity.platform.intuit.com
#127.0.0.1 rebill-sbg.api.intuit.com
127.0.0.1 appcenter.intuit.com
127.0.0.1 dev.visualwebsiteoptimizer.com