AAD Login Error: AADSTS90094 "Need Admin Approval"

[jrios6]

I deployed the Ibex-Dashboard according to the instructions and added authentication using my company's AAD. I made 'User Assignment Required' to be true under the AAD Application Settings, to restrict access to specific users in the AD to access the dashboard. From what I see, users can be assigned to the dashboard from the same panel in the AAD Application Local Directory Settings page.

However, when an account that I assigned as a user tries to sign in, there's a AADSTS90094 "Need Admin Approval" error. How do I fix this?