Jira issue's change history manager has all the details that you need like what was changed, who did it and when.
#JiraRESTAPI #ChangeLog
End point: rest/api/3/issue/sd-26?expand=changelog
Jira Cloud REST API: https://developer.atlassian.com/cloud/jira/platform/rest/v3/
Jira Server REST API: https://docs.atlassian.com/software/jira/docs/api/REST/8.9.0/