When trying to connect your Microsoft calendar, you may see a screen like this:

This message appears because of the security settings in Microsoft Entra (Microsoft’s identity platform for managing sign-in and permissions) of your organization.
Some organizations block users from granting app permissions unless an administrator has approved the app to use those permissions first.
An admin in your organization needs to activate the workflow so users can request access to apps that require admin consent. Documentation here.
Steps for the admin:
Sign in to the Microsoft Entra admin center (https://entra.microsoft.com) using a Global Administrator account.
Navigate to Entra ID → Enterprise apps → Consent and permissions → Admin consent settings.
Under “Admin consent requests”, toggle “Users can request admin consent to apps they are unable to consent to” to Yes.
Click Save. The workflow may take up to an hour to become active.
Once this is done, you (the Garba user) can retry to connect your calendar and you should be offered the option to send a request for admin approval, and designated reviewers will get notified. After they have approved, you should be able to connect.