Apologize for facing issue on this. After reproducing this it was found that the doc was broken, which is now been updated, Thanks for bringing it to our attention.
Could you please ensure the app settings like
AAD_CLIENT_ID are named the same as what is referenced in your app’s staticwebapp.config.json.
Please check: https://learn.microsoft.com/en-us/azure/static-web-apps/assign-roles-microsoft-graph#configure-active-directory-authentication
Hope this helps.
Let us know, if further query or issue remains.