Go through the following steps to run a search query using Jira's REST API:

1. Open up RESTClient in the Firefox browser.
2. Set the Method to GET.

3. Enter http://localhost:8080/rest/api/2/search?jql=assignee=currentUser() into the URL textbox. Make sure that you change the URL to your Jira instance.
4. Select Basic authentication and enter your username and password.
5. Click on the SEND button.

You should see the result of the API call under the Response section. Select the Preview tab to see the result as formatted JSON, as shown in the following screenshot:

The result of the API call is now visible.