Follow the below-mentioned steps to fetch the details of users using their account ID:

Step 1: Log in to your Jira account.

Step 2: Get your API Key using this help guide link. Note the API Key.

Step 3: Note the user Account IDs provided, since those will be used in the next step. Use the account ids in the Rest URL as shown below.

Step 4: Upload the collection into the Postman tool.

Step 5: Execute the following API:

• Method: GET

• Rest API endpoint: <https://your-domain.atlassian.net/rest/api/3/user?accountId=<Account> ID of the user>
  Example: https://qtmj.atlassian.net/rest/api/3/user?accountId=5bf3a00bb4cec3117e775462

• Header: Update API key as obtained in Step 2.