Prerequisites
You have (global) admin rights.
You have registered the app.
Steps
Open the Microsoft Entra admin center: https://entra.microsoft.com
Go to Applications.
Select the App registrations tab.
The App registrations tab opens.App registrations page in Microsoft Entra admin center
Select the entry of your app registration.
The Overview tab of your app registration opens.Registered app in Microsoft Entra admin center
Select the Authentication tab.
The Authentication tab opens.Authentication tab
In the Implicit grant and hybrid flows section select the checkboxes:
Access tokens
ID tokens
Authentication tab
In the Advanced Settings section keep Allow public client flow set on No.
Authentication tab
Select the Save button.
Result
You have granted token permissions to your app registration in Entra ID.