The mappings used by the connector are defined as records of the IHC Mappings Jira to PSA custom metadata type. The Integration Hub Connector: Jira - PSA provides default mappings that can be used out-of-the-box. Depending on your requirements, you can modify existing or create new mappings. For a full list of default mappings, see IHC Mappings Jira to PSA Default Records.
For steps on how to create or edit mappings, see the following: