I am trying to switch my app from username/password to JWT since the former is being phased out. I created a production JWT token (initially one for all my apps, and when that didn't work one specific to my app) and updated my production app to set it to JWT auth flow. However when I run this:

...

rcsdk = SDK(RINGCENTRAL_CLIENT_ID, RINGCENTRAL_CLIENT_SECRET, RINGCENTRAL_SERVER_URL)

platform = rcsdk.platform()

platform.login(jwt=JWT_TOKEN)

The code fails on the last line with "Unauthorized for this grant type". Anyone know what is wrong? Thanks.