Hi @Rodrigo Brechard ,
Thanks for reaching out.
I understand you are trying to authenticate the application with Educational API and getting "Need admin approval" even though permissions are granted by Admin.
I tried to repro the scenario with the permissions and settings mentioned by you using authorization code flow and able to get the access token successfully with required permissions.
Below are the settings in my organization
Only difference I can see with yours is your application registered in Default directory. Are you access the Azure portal using your personal account? I replicate that scenario as well in my lab with personal account and able to authenticate the user with required permissions.
Could you please verify again the settings of your tenant as mentioned above.
Are you facing the similar issue for other applications as well?
Also, could you check the URL you access doesn't have prompt=admin_consent which require admin approval?