post https://sandbox.api.plumguide.com/authenticate
Before using the Plum API it is necessary to authenticate. This is done by the sending of your ClientId and Client Secret in the response you will receive back a Token.
The token looks something like this (shortened - a real one will be much longer):
Bearer eyJhbGciOsdfg4433gbdf
This must be sent in the Authorization header of any subsequent request.