Documentation for creating Apple VPP token needs to be updated

The documentation on how to get a VPP token from Apple Business Manager (ABM) needs to be updated. The steps have changed since the document was created.

See the heading "Download Server Token" in the document here:

https://www.manageengine.com/mobile-device-management/help/app_management/ios_app_management.html

IBM has an updated guide that I followed successfully here:

https://www.ibm.com/support/pages/how-get-vpp-token-apple-business-manager