How to find User details using their account ID?

Option 1: From the Jira instance/ browser:

Admin can export all the user details in CSV format from Jira using his/her account. Follow the steps mentioned in this Atlassian documentation. The exported csv file contains the user id(account id), user name, email id, and other user details.

Option 2: Using API URL

Another alternative way to fetch the user details based on the user account id is using an API URL. Below are the steps.

Step 1: Log in to your Jira instance.

Step 2: Open another tab and paste the below URL. Replace the base URL with your Jira base URL (for example, https://your-domain.atlassian.net) and add the AccountID of the user for which you would like to fetch the user details.

https://<Jira base URL>/rest/api/3/user?accountId=<AccountID of the user>

Note: The above URL will provide only the user details as per the account id.