Edit: I have learned that next-gen projects have their own referenced ids for their IssueTypes.
So the error response I was seeing:
"Field 'summary' cannot be set. It is not on the appropriate screen, or unknown.","description":"Field 'description' cannot be set. It is not on the appropriate screen, or unknown.","labels":"Field 'labels' cannot be set. It is not on the appropriate screen, or unknown."
can come from the Atlassian api when the project is a next-gen project, and the issueType doesn’t belong to that project. “Classic” jira projects will share issueTypes, whereas next-gen projects will have unique issueTypes for their own project.