What JSON do I send when sending a POST using the JIRA REST API?

I use / rest / api / 2 / screens / {screenId} / tabs / {tabId} / fields in the POST fields on the JIRA tab, but I cannot figure out how the JSON should be structured, which I POSTING.

I get this error message that is extremely difficult to understand (and Google provided minimal help): string(298) "{"errorMessages":["Unrecognized field \"id\" (Class com.atlassian.jira.rest.v2.issue.AddFieldBean), not marked as ignorable\n at [Source: org.apache.catalina.connector.CoyoteInputStream@5383f8a; line: 1, column: 8] (through reference chain: com.atlassian.jira.rest.v2.issue.AddFieldBean[\"id\"])"]}"

Here is the JSON I'm sending now: '{"id":"customfield_11930","name":"1st Review Ready"}';