If you're in a room and invited to the stage to speak by one of the moderators, you'll receive a shortcut message that you can select to "Join the stage."
This will temporarily replace the standard Hand Raise button.
Need to activate VoiceOver or TalkBack?
If you need to activate VoiceOver or TalkBack on your device, the following article may be helpful: How do I activate VoiceOver & TalkBack with my mobile device?