API to access MS forms

This is my set up (set up from scratch to test it), hopefully it can help narrow down the problem:

1. Set up a basic App registration (single tenant, no redirect URI). 
2. Copy the application (client) ID
3. Set up a secret. Copy the secret.
4. NO API PERMISSIONS REQUIRED (as of writing this). This is strange, but for some reason, it works (for now)
5. log into forms through your browser, then open a new tab and go to the following: https://forms.office.com/formapi/api/userInfo
6. Grab the (user) id from that response, and use it in the following: https://forms.office.com/formapi/api/{Tenant_id}/users/{User_id}/forms
7. Grab a (form) id from that response and now try the following: https://forms.office.com/formapi/api/{Tenant_id}/users/{User_id}/forms

8. Testing in postman, authenticate using the following and copy the token:

   POST to "https://login.microsoftonline.com/{TenantID}/oauth2/v2.0/token"

   Body:

   • grant_type = client_credentials
   • client_id = {app_id copied}
   • client_secret = {app_secret copied}
   • scope = https://forms.office.com/.default
     • (@mpheasent used this with success as well: api://forms.office.com/c9a559d2-7aab-4f13-a6ed-e7e9c52aec87/.default)

9. Replicate the responses call with postman (note the URL encoding of (''):

GET "https://forms.office.com/formapi/api/{Tenant_id}/users/{user_id}/forms%28%27{Form_id}%27%29/responses"

Headers:

• Authorization = Bearer {token}

Haven't figured out a single call to to get all forms for all users yet either. Hope this helps someone nonetheless.