When attendees want their sessions to show up in their own Outlook calendar, Amego needs permission from your organization's Azure AD tenant to write those events on their behalf. Because that permission touches every user in your directory, it has to be granted by an Azure AD admin — an individual attendee clicking "allow" isn't enough.
In the Azure portal, go to Azure Active Directory, then App registrations, and locate the Amego integration (or add it if this is the first time you're connecting). Under API permissions, you'll see the specific Microsoft Graph scopes Amego requests — typically calendar read/write access scoped to the individual user, not the full directory. Review these before granting anything; you should only see permissions related to calendar access, not broader mail or profile scopes.
Once you're satisfied with the requested scopes, click Grant admin consent for your organization. This is the step that actually activates the sync for your whole tenant — until an admin does this, attendees will hit a permissions error when they try to connect their calendar, even if they personally approve the request.
If your organization has conditional access policies or restricts third-party app consent by default, you may need to add Amego to an approved app list separately before the consent grant will take. When in doubt, loop in whoever manages your conditional access policies before you troubleshoot the sync itself — most "it's not working" reports trace back to a consent or policy block rather than anything on the Amego side.