I am unable to get the overview of the payload provided for the claim request

Hello,
I am trying to learn about the payload structure of the claim request api and unable to understand the data they are adding in the base64 payload.
https://sbxhcx.abdm.gov.in/claimhcxservice/swagger-ui/index.html?configUrl=/claimhcxservice/api-docs/swagger-config#/V1.0%20APIs-Payer%20side/claimSubmitPost