There are two ways to manage a linked query: you can either create a new linked query, or use a saved linked query to your sheet.
Let's explore the methods:
To create a new linked query, paste your desired query and click the checkbox to "link this query to [your] current sheet." Then click save, and you will have a new query automatically linked and pre-loaded on your Google sheet when you launch the add-on. To see how to link a specific query, go to this article.
To access a saved linked query, go to the saved tab. Within the "manage linked queries section," click "add new link," select the query you'd like to use and the corresponding sheet, and link the query.