I have attended several RootsTech, and the RootsTech App has allowed us to find relatives among attendees. RootsTech Virtual 2021 doesn’t use the RootsTech App, but you could download the app Family Tree from App Store or Google Play. Log in with your Family Search Account, and make sure you have a family tree on Family Search. On top of your screen, it will show an option to find relatives at RootsTech. It will show a list of relatives who also have uploaded a family tree to Family Search, and how you are related. In this case, I have a cousin who is my 6th cousin twice removed.
Combine this app with your DNA matches, and you might be able to solve some family history mysteries too.