Within a Microsoft 365 account, some permissions require the explicit approval of an administrator. That means admin consent must be granted even before you log into InterviewPlanner for the first time.
If admin consent was granted prior to creating your InterviewPlanner account, but it was later removed, you can follow this same workflow to re-grant the consent and restore everything back to working order.
If you are a Microsoft administrator
If you are an admin, then you'll be able to grant consent on behalf of your organization. You can visit the Admin Consent page and click on the Grant Admin Consent button. This will take you through the process of granting consent.
If you are not a Microsoft administrator
In the likely scenario where you're not an admin, you'll need to send a link to the Admin Consent page to one of your Microsoft administrators. They don't need to have an InterviewPlanner account or be signed in. They just need to click on the Grant Admin Consent button and go through the process.
If your Microsoft administrator set up admin consent requests
Within a Microsoft organization's settings, your admin might have enabled admin consent requests. This means that if you are not an admin, you'll be able to send a request to a preselected group of admins, all through the Microsoft workflow.
To do this, you can go to the sign-in or sign-up pages and attempt to sign in. This should inform you that approval is required, and you'll need to enter justification for requesting this app.
Remember, this will only appear if your admins have configured this previously.
If you're not sure if you're a Microsoft administrator
If you're not sure if you are an admin or not, there's no harm in trying to grant consent. If you end up not being an admin, it will tell you that you need an admin's approval.