How can we get Authentication token and use it via REST API in PeopleSoft

PeopleSoft (not on cloud)

Application 9.2.042

Tools8.60

We are implementing REST API to send some peopelsoft data as status to third party system. Before call the API we need to call the token service provider to get the Authentication token via API for the client id, grant type & assertion type which they given along with a client assertion, which needs to be generated in Peopelsoft via given payload.

How can this be done in PeopleSoft and how can we use the token in JSON parser to call the main API.

please provide guidance If any one has implemented certificate based authentication from PeopleSoft to third party to get a access token, using PeopleSoft integration broker.