To configure the automatic selection of a query based on a query string, set the value of the showSingleQuery key to true, the selectedQueryId key to null, and for the selectedQueryIdQSField key, specify a query string field to hold the query ID. For example:
"showSingleQuery": true
"selectedQueryId": null,
"selectedQueryIdQSField": "CQID"
Then, include the created field in the query string appended to the URL, and set its value to the ID number of the Custom Query to select. For example, a URL with the following query string could be used to preselect Custom Query #103:
?CQID=103
For more information on query strings, see Using Query Strings.