Authorization and permissions request

In this step, you will see a permissions request. Click “Login to Azure AD.”
Virto Calendar App Getting Started
If you have tenant administrator rights, check "Consent on behalf of your organization" and click "Accept." Alternatively, contact your tenant administrator to do this.
If you don't receive this alert message, just skip this step.
Virto Calendar App Getting Started
Calendar Overlay Pro requests permissions, but they are delegated. This means they are activated only by a particular user from your company with their permission. These permissions are required to let the calendar overlaying feature work.
You can find further details of this step in the"Calendar App Update: New Authorization Process" article.