async function lookupReporter(testerEmail) {
  const response =
        await fetch(
            `${jiraUriConfig.value()}/rest/api/3/user/search` +
              `?query=${testerEmail}`, {
              method: "GET",
              headers: {
                "Authorization": authHeader(),
                "Accept": "application/json",
              }});
  if (!response.ok) {
    logger.info(`Failed to find Jira user for '${testerEmail}':` +
                `${response.status} ${response.statusText}`);
  }
  const json = await response.json();
  return json.length > 0 ? json[0].accountId : undefined;
}
Looks up Jira user ID.
@param {string} testerEmail Email address of tester who filed feedback